BIRDS OF THE JEHOL BIOTA

In November 1993, Chinese paleontologists Hou Lianhai and Hu Yoaming, of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing received a call from an excited local fossil collector.

He claimed to have quite a remarkable specimen on his hands. The team visited Zhang He at his home in Jinzhou, or Chinchow, a coastal prefecture-level city in central-west Liaoning province

Zhang showed them a spectacular fossil bird specimen he'd recently purchased at a local flea market. Very little was known about the specimen but it was clearly important and the team was hopeful more of this paleo goodness might turn up.

They didn't have that long to wait. A month after his visit to Zhang, Hou learned about a second specimen discovered by a local farmer, Yang Yushan. Things were looking up. Best of all, he learned that both specimens were likely from the same locality in Shangyuan, Beipiao. This was not a one-off discovery or an amazing but anonymous find. With two specimens to compare, the locality determined, the possibility of an interesting publication and career advancement would be a reality.

In 1995, the two specimens, as well as a third, were formally described as a new genus and species, Confuciusornis sanctus, by Hou and colleagues. The generic name combines the philosopher Confucius with a Greek ὄρνις, (ornis), "bird". The specific name means "holy one" in Latin and is a translation of Chinese 圣贤, shèngxián, "sage", again in reference to Confucius.

The first discovered specimen was designated the holotype (as you do) and catalogued under the specimen number IVPP V10918; it comprises a partial skeleton with skull and parts of the forelimb.

Of the other two skeletons, one (paratype, IVPP V10895) comprises a complete pelvis and hind limb, and the other (paratype, IVPP V10919–10925) a fragmentary hind limb together with six feather impressions attached to both sides of the tibia or shin bone.

All was well until those reading the journal articles realized that the two paratype specimens only comprise bones that were unknown from the holotype. An oversight, likely by design, but this lack of overlap between the specimens made their referral to the species speculative. The lack of overlap also gave a wide margin for error in the naming of additional, albeit hopeful, new species names — names that would later need to be amended. Luckily, the discovery of a veritable treasure trove of well-preserved specimens shortly after confirmed that the specimens indeed represented a single species.

Together with the early mammal Zhangheotherium, which was discovered about the same time, Confuciusornis was considered the most remarkable fossil discovery of the Jehol biota. If you're not in the paleo loop, the Jehol biota of northeastern China has unearthed some of the most important Mesozoic bird specimens worldwide over the past two decades.

It has also given us another fossil-rich Lagerstätte that includes a wonderful mix of advanced and ancient species. My speculation is that northeast Asia was isolated for part of the Jurassic by the Turgai Sea that separated Europe from Asia at that time. The fossils at Jehol are numerous and exceptionally well preserved. Think of the Cambrian goodies at Burgess or the Altmühltal Formation, Jurassic Konservat-Lagerstätte at Solnhofen. Quite remarkably, fully articulated skeletons, soft tissues, colour patterns, stomach contents, and twigs with leaves and flowers still attached, can be found within the Jehol biota.

A beautifully preserved Archaeopteryx

In the late 1990s, Confuciusornis was considered both the oldest beaked bird as well as the most primitive bird after Archaeopteryx. It was also considered to be only slightly younger than Archaeopteryx. 

Yixian Formation, the rock unit where most Confuciusornis specimens have been found, was thought to be of Late Jurassic (Tithonian) age at the time.

Although two bird genera, Sinornis and Cathayornis, had already described from the Jehol biota back in 1992, these were based on fragmentary remains and stem from the younger Jiufotang Formation. At the time, the Jiufotang was thought to be Early Cretaceous. Both formations have since been dated to the Lower Cretaceous — Barremian to Aptian — 131–120 million years ago.

In 1995, local farmers began digging for fossils near the village of Sihetun, Beipiao, in what would become one of the most productive localities of the Jehol biota. The then largely unknown site is truly world-class. Large-scale professional excavations at this single locality have been carried out by the IVPP from 1997 onwards. Not one, not two, but several hundred specimens of Confuciusornis have now been unearthed from here. Many additional sites producing fossils of the Jehol biota have been recognized since, distributed over a large region including Liaoning, Hebei, and Inner Mongolia.

Due to the great abundance, preservation, and commercial value of the fossils, excavations by local farmers produced an unusually high number of fossils. Although some of these fossils have been added to the collections of Chinese research institutions, more have been smuggled out of the country.

In 1999, it was estimated that the National Geological Museum of China in Beijing housed nearly a hundred (100) specimens of Confuciusornis, and in 2010, the Shandong Tianyu Museum of Nature was reported to possess five hundred and thirty-six (536) specimens. While it is illegal to export them, the majority of specimens are still held privately and thus are not available for research. I see them on social media and occasionally they come up for sale on eBay.

At one time forty individuals were discovered on a surface of about 100 m2. This unusual bone bed was likely the result of an entire flock of birds being simultaneously killed by ash, heat or poisonous gas following the volcanic eruptions that caused the tuff stone in which the fossils were found to be deposited as lake sediments. An avian death bed is highly unusual. Very sad for our feathered friends but grateful for what has been revealed by this rare event.

Notes: Confuciusornis chuonzhous was named by Hou in 1997 based on specimen IVPP V10919, originally a paratype of Confuciusornis sanctus. The specific name refers to Chuanzhou, an ancient name for Beipiao. Confuciusornis chuonzhous is now generally considered synonymous with Confuciusornis sanctus.

Confuciusornis suniae, named by Hou in the same 1997 publication, was based on specimen IVPP V11308. The specific name honours Madam Sun, the wife of Shikuan Liang who donated the fossil to the IVPP. Confuciusornis suniae is now usually considered synonymous with Confuciusornis sanctus.

Reference: Zhou, Z; Hou, L. (1998). "Confuciusornis and the early evolution of birds". Vertebrata PalAsiatica. 36 (2): 136–146.

Zhou, Z. (2006). "Evolutionary radiation of the Jehol Biota: chronological and ecological perspectives". Geological Journal. 41 (3–4): 377–393. doi:10.1002/gj.1045.

CALAMOPLEURUS OF BRAZIL

This well-preserved fossil fish skull is from Calamopleurus (Agassiz, 1841), an extinct genus of bony fishes related to the heavily armoured ray-finned gars.

They are fossil relics, the sole surviving species of the order Amiiformes. Although bowfins are highly evolved, they are often referred to as primitive fishes and living fossils as they retain many of the morphologic characteristics of their ancestors.

This specimen was found in Lower Cretaceous outcrops of the Santana Formation in the Araripe Basin UNESCO Global Geopark. The Santana Formation of north-east Brazil contains one of the most important Mesozoic fossil Konservat Lagerstatten on Gondwana (Maisey, 1991; Martill, 1993, 1997, 2001; Kellner, 2002; Fara et al., 2005). The formation crops out on the flanks of the Chapada do Araripe in southern Ceara´, western Pernambuco and a small part of eastern Piaui in the north-eastern Brazilian Caatinga. It forms part of a heterogeneous assemblage of spectacularly fossiliferous rocks of Cretaceous age (Gardner, 1841; Brito, 1984; Maisey, 1991; Martill, 1993).

Two formations within the basin are well-known as Konservat Lagerstatten; the Nova Olinda Member of the Crato Formation lies a few tens of metres below the Santana Formation, and both have contributed considerably to our knowledge and understanding of Gondwanan Cretaceous palaeobiotas (Martill, 1988, 1993; Wenz and Brito, 1990; Maisey, 1991, 1993; and many references herein). Only the age of the Romualdo Member of the Santana Formation, a dominantly silty shale sequence that includes the highly fossiliferous carbonate concretion-bearing unit, is considered here.

Although the Santana Formation concretions have been famous for their enclosed fossils, especially fishes, for over 150 years, in more recent times they have become known for a diversity of dinosaur and pterosaur remains in an excellent state of preservation (Martill, 1998; Martill and Unwin, 1989; Kellner, 1996a,b; Frey et al., 2003a,b) comparable with, and sometimes exceeding, that of the Jurassic Solnhofen Limestone of Bavaria (Barthel et al., 1990), especially in their three-dimensionality. Photo and collection of David Murphy.

References: Martill, David M. The age of the Cretaceous Santana Formation fossil Konservat Lagerstatten of north-east Brazil: a historical review and an appraisal of the biochronostratigraphic utility of its palaeobiota, Cretaceous Research 28 (2007) 895-920.

THEROPODS OF A FEATHER

Birds are a group of warm-blooded vertebrates constituting the class Aves, characterized by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton.

These modern dinosaurs live worldwide and range in size from the 5 cm (2 in) bee hummingbird to the 2.75 m (9 ft) ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds.

Birds have wings whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds.

Wings, which evolved from forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming.

Best of all, birds are feathered theropod dinosaurs, and constitute the only living dinosaurs. Based on fossil and biological evidence, most scientists accept that birds are a specialized subgroup of theropod dinosaurs, and more specifically, they are members of Maniraptora, a group of theropods which includes dromaeosaurs and oviraptorids, amongst others. As palaeontologists discover more theropods closely related to birds, the previously clear distinction between non-birds and birds has become a bit muddy.

Recent discoveries in the Liaoning Province of northeast China, which include many small theropod feathered dinosaurs — and some excellent fakes — contribute to this ambiguity. Still, other fossil specimens found here shed a light on the evolution of Aves. Confuciusornis sanctus, an Early Cretaceous bird from the Yixian and Jiufotang Formations of China is the oldest known bird to have a beak.

Like modern birds, Confuciusornis had a toothless beak, but close relatives of modern birds such as Hesperornis and Ichthyornis were toothed, telling us that the loss of teeth occurred convergently in Confuciusornis and living birds.

Confuciusornis sanctus, Cretaceous Bird from China, 125 mya

The consensus view in contemporary palaeontology is that the flying theropods, or avialans, are the closest relatives of the deinonychosaurs, which include dromaeosaurids and troodontids.

Together, these form a group called Paraves. Some basal members of this group, such as Microraptor, have features which may have enabled them to glide or fly. The most basal deinonychosaurs were wee little things. This evidence raises the possibility that the ancestor of all paravians may have been arboreal, have been able to glide, or both. Unlike Archaeopteryx and the non-avialan feathered dinosaurs, who primarily ate meat, tummy contents from recent avialan studies suggest that the first avialans were omnivores. Even more intriguing...

Avialae or "bird wings" are a clade of flying dinosaurs containing the only living dinosaurs, the birds. It is usually defined as all theropod dinosaurs more closely related to modern birds (Aves) than to deinonychosaurs, though alternative definitions are occasionally bantered back and forth.

Archaeopteryx lithographica, from the late Jurassic Period Solnhofen Formation of Germany, is the earliest known avialan which may have had the capability of powered flight. However, several older avialans are known from the Late Jurassic Tiaojishan Formation of China, dating to about 160 million years ago.

The Late Jurassic Archaeopteryx is well-known as one of the first transitional fossils to be found, and it provided support for the theory of evolution in the late 19th century. Archaeopteryx was the first fossil to clearly display both traditional reptilian characteristics — teeth, clawed fingers, and a long, lizard-like tail—as well as wings with flight feathers similar to those of modern birds. It is not considered a direct ancestor of birds, though it is possibly closely related to the true ancestor.

Unlikely yet true, the closest living relatives of birds are the crocodilians. Birds are descendants of the primitive avialans — whose members include Archaeopteryx — which first appeared about 160 million years ago in China.

DNA evidence tells us that modern birds — Neornithes — evolved in the Middle to Late Cretaceous, and diversified dramatically around the time of the Cretaceous–Paleogene extinction event 66 mya, which killed off the pterosaurs and all non-avian dinosaurs.

In birds, the brain, especially the telencephalon, is remarkably developed, both in relative volume and complexity. Unlike most early‐branching sauropsids, the adults of birds and other archosaurs have a well‐ossified neurocranium. In contrast to most of their reptilian relatives, but similar to what we see in mammals, bird brains fit closely to the endocranial cavity so that major external features are reflected in the endocasts. What you see on the inside is what you see on the outside.

This makes birds an excellent group for palaeoneurological investigations. The first observation of the brain in a long‐extinct bird was made in the first quarter of the 19th century. However, it was not until the 2000s and the application of modern imaging technologies that avian palaeoneurology really took off.

Understanding how the mode of life is reflected in the external morphology of the brains of birds is but one of several future directions in which avian palaeoneurological research may extend.

Although the number of fossil specimens suitable for palaeoneurological explorations is considerably smaller in birds than in mammals and will very likely remain so, the coming years will certainly witness a momentous strengthening of this rapidly growing field of research at the overlap between ornithology, palaeontology, evolutionary biology and the neurosciences.

Reference: Cau, Andrea; Brougham, Tom; Naish, Darren (2015). "The phylogenetic affinities of the bizarre Late Cretaceous Romanian theropod Balaur bondoc (Dinosauria, Maniraptora): Dromaeosaurid or flightless bird?". PeerJ. 3: e1032. doi:10.7717/peerj.1032. PMC 4476167. PMID 26157616.

Reference: Ivanov, M., Hrdlickova, S. & Gregorova, R. (2001) The Complete Encyclopedia of Fossils. Rebo Publishers, Netherlands. p. 312

Photo: By Tommy from Arad - Confuciusornis; FunkMonk, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=24115307

SALTRIO THEROPOD

In the summer of 1996, Angelo Zanella, an avocational fossil collector and active collaborator at the Museo di Storia Naturale di Milano (MSNM) spotted some intriguing fossil bone sticking out of a large block of rock while hunting for ammonites in the Salnova marble quarry.

The quarry is in the Alpine foothills, at the Swiss–Italian border near Saltrio. Saltrio is about 80 km north of Milan in the province of Varese, Lombardy, Italy.

Zanella reported the bones to the MSNM, which arranged a paleontological expedition to the site. The research was difficult because the explosives used for industrial quarrying had blown up the fossil-bearing layer and had broken it into hundreds of pieces.

The Saltrio quarry has been active since the 15th century as one of the finest sites of marble production, and the “Saltrio Stone” provides high-quality building materials for many famous Italian monuments  — the Scala Opera House in Milan and the Mole Antonelliana in Turin. They actively use dynamite to extract the marble. Great for the workers who are not required to manually break-up the massive pieces. Less so for the fossils. The bones from the Saltrio theropod were blown to bits just prior to Zanella's discovery then had to be pieced back together.

Three years later, after 1,800 h of chemical preparation in the Laboratory of the MSNM, 132 remains were extracted from three main blocks. Although fragmentary, jaw fragments, one tooth, rib remains, pectoral and limb bones were analyzed and found to be that of a large theropod dinosaur.

The Saltrio theropod (MSNM V3664) became popular by the name, Saltriosauro, and so it was reported (Dal Sasso, 2001a) and preliminarily described (Dal Sasso, 2001b, 2004).

Pictured above: selected elements used in the diagnosis of Saltriovenator zanellai n. gen. n. sp. Right humerus in medial (A), frontal (B) and distal (C) views; (D) left scapula, medial view; (E) right scapular glenoid and coracoid, lateral view; (F) furcula, ventral view; tooth, labial (G) and apical (H) views; (I) left humerus, medial view; right second metacarpal in dorsal (J), lateral (L) and distal (N) views; first phalanx of the right second digit in dorsal (K), lateral (M) and proximal (O) views; (P–T) right third digit in proximal, dorsal and lateral views; (U) right distal tarsal IV, proximal view; third right metatarsal in proximal (V) and frontal (X) views; second right metatarsal, proximal (W) and frontal (Y) views; (Z) reconstructed skeleton showing identified elements (red). Abbreviations as in text, asterisks mark autapomorphic traits. Scale bars: 10 cm in (A)–(E), (I), and (U)–(Y); two cm in (F), and (J)–(T); one cm in (G).

Photos by G. Bindellini, C. Dal Sasso and M. Zilioli; drawing by M. Auditore. - https://peerj.com/articles/5976/

ANEMONEFISH NURSERY

Anemonefish colonies usually consist of the reproductive male and female and a few male juveniles, which help tend the colony.

Although multiple males cohabit an environment with a single female, polygamy does not occur and only the adult pair exhibits reproductive behaviour. If the female dies, the social hierarchy shifts with the breeding male exhibiting protandrous sex reversal to become the breeding female.

The largest juvenile then becomes the new breeding male after a period of rapid growth. The existence of protandry in anemonefish may rest on the case that nonbreeders modulate their phenotype in a way that causes breeders to tolerate them. This strategy prevents conflict by reducing competition between males for one female. For example, by purposefully modifying their growth rate to remain small and submissive, the juveniles in a colony present no threat to the fitness of the adult male, thereby protecting themselves from being evicted by the dominant fish.

The reproductive cycle of anemonefish is often correlated with the lunar cycle. Rates of spawning for anemonefish peak around the first and third quarters of the moon. The timing of this spawn means that the eggs hatch around the full moon or new moon periods. One explanation for this lunar clock is that spring tides produce the highest tides during full or new moons. Nocturnal hatching during high tide may reduce predation by allowing for a greater capacity for escape. Namely, the stronger currents and greater water volume during high tide protect the hatchlings by effectively sweeping them to safety. Before spawning, anemonefish exhibit increased rates of anemone and substrate biting, which help prepare and clean the nest for the spawn.

In terms of parental care, male anemonefish are often the caretakers of eggs. Before making the clutch, the parents often clear an oval-shaped clutch varying in diameter for the spawn. Fecundity, or reproductive rate, of the females, usually ranges from 600 to 1500 eggs depending on her size. In contrast to most animal species, the female-only occasionally takes responsibility for the eggs, with males expending most of the time and effort. Male anemonefish care for their eggs by fanning and guarding them for 6 to 10 days until they hatch. In general, eggs develop more rapidly in a clutch when males fan properly, and fanning represents a crucial mechanism of successfully developing eggs.

This suggests that males can control the success of hatching an egg clutch by investing different amounts of time and energy towards the eggs. For example, a male could choose to fan less in times of scarcity or fan more in times of abundance. Furthermore, males display increased alertness when guarding more valuable broods, or eggs in which paternity was guaranteed. Females, though, display generally less preference for parental behavior than males. All these suggest that males have increased parental investment towards the eggs compared to females.

CLOWN FISH: SYMBIOSIS

The colourful wee fellows you see here are Clown Fish. They have an unusual relationship with sea anemones. Clownfish or anemonefish are fishes from the subfamily Amphiprioninae in the family Pomacentridae. Thirty species are recognized: one in the genus Premnas, while the remaining are in the genus Amphiprion.

In the wild, they all form symbiotic mutualisms with sea anemones, each providing benefits to the other.

The individual species are generally highly host-specific, and especially the genera Heteractis and Stichodactyla, and the species Entacmaea quadricolor are frequent anemonefish partners.

The sea anemone protects the anemonefish from predators, as well as providing food through the scraps left from the anemone's meals and occasional dead anemone tentacles, and functions as a safe nest site. In return, the anemonefish defends the anemone from its predators and parasites.

The anemone also picks up nutrients from the anemonefish's excrement. The nitrogen excreted from anemonefish increases the number of algae incorporated into the tissue of their hosts, which aids the anemone in tissue growth and regeneration.

The activity of the anemonefish results in greater water circulation around the sea anemone, and it has been suggested that their bright colouring might lure small fish to the anemone, which then catches them. Studies on anemonefish have found that they alter the flow of water around sea anemone tentacles by certain behaviours and movements such as "wedging" and "switching". Aeration of the host anemone tentacles allows for benefits to the metabolism of both partners, mainly by increasing anemone body size and both anemonefish and anemone respiration.

SEA ANEMONE NURSERY

Sea anemones are familiar inhabitants of rocky shores and coral reefs around the world; other species can be found at very low depths indeed. Most of the soft-bodied anthozoans known as "sea anemones" are classified in the Actinaria.

Most actinarians are sessile; that is, they live attached to rocks or other substrates and do not move, or move only very slowly by contractions of the pedal disk. A number of anemones burrow into sand, and a few can even swim short distances, by bending the column back and forth or by "flapping" their tentacles. In all, there are about 1000 species of sea anemone in the world's oceans.

Sea anemones breed by liberating sperm and eggs through their mouth into the sea. The fertilized eggs develop into planula larvae which, after being planktonic for a while, settle on the seabed and develop directly into juvenile polyps. Sea anemones can also breed asexually, by breaking in half or into smaller pieces which regenerate into polyps.

They are sometimes kept in reef aquariums; the global trade in marine ornamentals is expanding and threatens sea anemone populations in some localities, as the trade depends on collection from the wild. Most Actiniaria do not form hard parts that can be recognized as fossils, but a few fossils of sea anemones do exist; Mackenzia, from the Stephen Formation, Middle Cambrian Burgess Shale of Canada, is the oldest fossil identified as a sea anemone.

Some fossil sea anemones have also been found from the Lower Cambrian of China. The new find lends support to genetic data that suggests anthozoans — anemones, corals, octocorals and their kin — were one the first Cnidarian groups to diversify.

Reference:  Conway Morris, S. (1993). "Ediacaran-like fossils in Cambrian Burgess Shale–type faunas of North America". Palaeontology. 36 (31–0239): 593–635.

SEA ANEMONES: MARINE PREDATORS

Sea Anenome on Coral Reef

Sea anemones are a group of predatory marine animals in the order Actiniaria. They are named after the anemone, a terrestrial flowering plant because of the colourful appearance of so many of these lovelies.

Sea anemones are in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra.

Unlike jellyfish, sea anemones do not have a medusa stage in their life cycle. A typical sea anemone is a single polyp attached to a hard surface by its base, but some species live in soft sediment and a few float near the surface of the water. The polyp has a columnar trunk topped by an oral disc with a ring of tentacles and a central mouth.

The tentacles can be retracted inside the body cavity or expanded to catch passing prey. They are armed with cnidocytes (stinging cells). In many species, additional nourishment comes from a symbiotic relationship with single-celled dinoflagellates, zooxanthellae or with green algae, zoochlorellae, that live within the cells. Some species of sea anemone live in association with hermit crabs, small fish or other animals to their mutual benefit.

SEXUAL DIMORPHISM

Despite the differences between these two ammonites, both represent the same species, Macroscaphites yvani. The difference you see here is caused by sexual dimorphism. The larger of these is the female macroconch and the smaller specimen is the male of the species. These beauties are in the collection of the deeply awesome José Juárez Ruiz.

NOTOCHORDS AND SPINAL COLUMNS

Having a backbone or spinal column is what sets apart you, me and almost 70,000 species on this big blue planet.

So which lucky ducks evolved one? Well, ducks for one. Warm-blooded birds and mammals cheerfully claim those bragging rights. They're joined by our cold-blooded, ectothermic friends, the fish, amphibians and reptiles. All these diverse lovelies share this characteristic.

And whether they now live at sea or on land, all of these lineages evolved from a marine organism somewhere down the line, then went on to develop a notochord and spinal column. Notochords are flexible rods that run down the length of chordates and vertebrates. They are handy adaptations for muscle attachment, helping with signalling and coordinating the development of the embryonic stage. The cells from the notochord play a key role in the development of the central nervous system and the formation of motor neurons and sensory cells. Alas, we often take our evolution for granted.

Let's take a moment to appreciate just how marvellous this evolutionary gift is and what it allows us to do. Your backbone gives your body structure, holds up that heavy skull of yours and connects your tasty brain to your body and organs. Eating, walking, fishing, hunting, your morning yoga class, are all made possible because of this adaptation. Pick pretty near anything you love to do and it is only possible because of your blessed spine. And it sets us apart from our invertebrate friends.

Arturia nautiloid, Olympic Peninsula

While seventy thousand may seem like a large number, it represents less than three to five percent of all described animal species. The rest is made up of the whopping 97%'ers, our dear invertebrates who include the arthropods (insects, arachnids, crustaceans, and myriapods), mollusks (our dear chitons, snails, bivalves, squid, and octopus), annelids (the often misunderstood earthworms and leeches), and cnidarians (our beautiful hydras, jellyfish, sea anemones, and corals).

You'll notice that many of our invertebrate friends occur as tasty snacks. Having a backbone provides a supreme advantage to your placement in the food chain. Not always, as you may include fish and game on your menu. But generally, having a backbone means you're more likely to be holding the menu versus being listed as an appetizer. So, enjoy your Sunday 'downward dog' and thank your backbone for the magical gift it is.

AUSTRALOPITHECUS AFRICANUS

Two views of a natural endocranial cast articulated with a fragmentary skull of Australopithecus africanus, an early hominid living between 2-3 million years ago in the late Pliocene and into the early Pleistocene -- and the first pre-human to be discovered. They shared many characteristics with their older relatives the Australopithecus afarensis including a more gracile body. The casts you see here show the left maxilla, the orbital area and most of the skull base.

Australopithecus africanus had a larger brain and more humanoid facial features than their older ancestors with an average endocranial volume of 485 cm3 (29.6 cu in). This specimen is TM 1511 and lives in the Ditsong National Museum of Natural History, an amalgamation of eight museums, seven in Tshwane and one in Johannesburg. These museums have diverse collections covering the fields of fauna and flora, palaeontology, military history, cultural history, geology, anthropology and archaeology. The museum is enjoyed by children, youth, adults, students, tourists (foreign and local), researchers and the public in general. The museum is in Pretoria, South Africa which straddles the Apies River and has spread eastwards into the foothills of the Magaliesberg mountains.

Prior to a closer look by researchers, the skull was incorrectly believed to be a separate species, Plesianthropus transvaalensis. It was first discovered in South Africa by G. W. Barlow and described by Robert Broom in 1938. Photo credit: José Braga and Didier Descouens.

CADOCERAS OF HARRISON LAKE

Cadoceras (Paracadoceras) tonniense

This lovely ammonite is Cadoceras (Paracadoceras) tonniense (Imlay, 1953), a fast-moving nektonic carnivore from the Jurassic macrocephalites macrocephalus ammonoid zone of the Mysterious Creek Formation near Harrison Lake in British Columbia. These specimens were found on the first paleontological field trip of 2020 by Vancouver Paleontological Society Vice-Chair, John Fam. They were rediscovering a few of the old GSC localities north of the main collecting outcrops.

These rare beauties are from the Lower Callovian, 164.7 - 161.2 million years ago. Interestingly, the ammonites from here are quite similar to the ones found within the lower part of the Chinitna Formation, Alaska and Jurassic Point, Kyuquot, on the west coast of Vancouver Island.

These species are from Callomon's (1984) Cadoceras comma Fauna B8 for the western Cordillera of North America, which is equivalent in part to the Macrocephalus Zone of Europe of the Early Callovian. The faunal association at locality 17 near Harrison suggests a more precise correlation to Callomon's zonation; namely, the Cadoceras wosnessenskii Fauna B8(e) found in the Chinitna Formation, southern Alaska (Imlay, 1953b). The type specimen is USNM 108088, from locality USGS Mesozoic 21340, Iniskin Peninsula, found in a Callovian marine siliciclastic in the Chinitna Formation of Alaska.

There are many fossils to be found on the west side of the Harrison lake near the town of Harrison, British Columbia. Exploration of the geology around Harrison Lake has a long history with geologists from the Geological Survey of Canada studying geology and paleontological exposures as far back as the 1880s. They were probably looking for coal exposures —  but happy day, they found fossils!

The paleo outcrops were first mentioned in the Geological Survey of Canada's Director's Report in 1888 (Selwyn, 1888), then studied by Whiteaves a year later. Whiteaves identified the prolific bivalve Aucella (now Buchia) from several specimens collected in 1882 by A. Bowman of the Geological Survey of Canada. The first detailed geological work in the Harrison Lake area was undertaken in a doctoral study by Crickmay (1925), who compiled a geological map, describing the stratigraphy and establishing the formational names, many of which we still use today. Crickmay went on to interpret the paleogeography and structure of the region. There was a time in the early 2000s, when Jim Haggart asked one of the VanPS members to take up the mantle and try to cherry-pick through a boatload of buchia finds to sort their nomenclature. I'm not sure if that project ever bore fruit.

Cadoceras (Paracadoceras) tonniense

Around Harrison Lake, Callovian beds of the Mysterious Creek Formation are locally overlain disconformably by 3,000 feet of Early Oxfordian conglomerate. We find Cadoceras tonniense here and at nine localities in the Alaska Peninsula and Cook Inlet regions of the USA.

If you'd like to visit the site at Chinitna Bay, you'll want to hike into 59.9° N, 153.0° W: paleo-coordinates 31.6° N, 86.6° W.

If you're a keen bean for the Canadian site, you can drive the 30 km up Forestry Road #17, stopping just past Hale Creek at 49.5° N, 121.9° W: paleo-coordinates 42.5° N, 63.4° W, on the west side of Harrison Lake. You'll see Long Island to your right. If you can pre-load the Google Earth map of the area you'll thank yourself. Pro tip: access Forestry Road #17 at the northeast end of the parking lot from the Sasquatch Inn at 46001 Lougheed Hwy, Harrison  Mills. Look for signs for the Chehalis River Fish Hatchery to get you started. NTS: 92H/05NW; 92H/05SW; 92H/12NW; 92H/12SW.

A. J. Arthur, P. L. Smith, J. W. H. Monger and H. W. Tipper. 1993. Mesozoic stratigraphy and Jurassic paleontology west of Harrison Lake, southwestern British Columbia. Geological Survey of Canada Bulletin 441:1-62

R. W. Imlay. 1953. Callovian (Jurassic) ammonites from the United States and Alaska Part 2. The Alaska Peninsula and Cook Inlet regions. United States Geological Survey Professional Paper 249-B:41-108

An overview of the tectonic history of the southern Coast Mountains, British Columbia; Monger, J W H; in, Field trips to Harrison Lake and Vancouver Island, British Columbia; Haggart, J W (ed.); Smith, P L (ed.). Canadian Paleontology Conference, Field Trip Guidebook 16, 2011 p. 1-11 (ESS Cont.# 20110248).

Photos: These photos are from the first paleontological field trip of 2020 by Vancouver Paleontological Society Vice-Chair, John Fam.

OUT OF AFRICA

The geology of South Africa is highly varied including cratons, greenstone belts, large impact craters as well as orogenic belts. The geology of the country is the base for a large mining sector that extracts gold, diamonds, iron and coal from world-class deposits.

The geomorphology of South Africa consists of a high plateau rimmed to west, south and southeast by the Great Escarpment and rugged mountains beyond this there is a strip of narrow coastal plain. The basement of much of the northeastern part of South Africa is made up of the Kaapvaal Craton. To the south and east, the craton is bordered by the Namaqua-Natal belt.

In Neoproterozoic times, much of South Africa stabilized into the large Kalahari Craton that came to form part of the supercontinent Rodinia. The Kalahari Craton was near the center of Rodinia with paleogeographic reconstructions indicating it was surrounded by the cratons of Laurentia, Río de la Plata, Congo and Dronning Maud Land. Evidence of this is the continuation of the Namaqua-Natal belt in East Antarctica indicating that South Africa and East Antarctica formed a single continent when this belt formed about 1000 million years ago.

Since the Mesozoic, the tectonics of South Africa has been shaped by an initial phase of rifting and then by episodic epeirogenic movements. South Africa is currently an elevated passive margin much like Eastern Greenland and the Brazilian Highlands.

The uplift of these margins is tentatively related to far-field compressional stresses that have warped the region as a giant anticline-like lithosphere fold. These tectonics have had a profound effect in shaping the Great Escarpment and uplifting, creating and destroying plateaux including the African Surface, a key reference surface.

On average, 2.5 to 3.5 km rock was eroded in the Mid to Late Cretaceous. Further erosion in Cenozoic times amounts to less than one kilometre. Limited erosion means that many of the major relief features of South Africa have existed since the Late Cretaceous. Warping of Southern Africa has led to significant changes in drainage basins with the Orange River likely losing a drainage area in the Kalahari Basin, the Limpopo River losing interior drainage areas to the Zambezi River and the west-draining Karoo River ceasing to exist altogether. Overall, the boundaries of the drainage basins coincide with the axes of uplifted epeirogenic flexures.

MAMMOTH LAST MEAL

One of the first scientific accounts of a well-preserved woolly mammoth (Mammuthus primigenius) frozen in Siberia described the meat as enticingly red and marbled but smelling so putrid that researchers could only tolerate a minute in its proximity.

Despite this initial review, numerous apocryphal tales exist of dinners made from centuries-old mammoths found frozen whole in clear blocks of ice. These accounts have not only enchanted the public but also heavily influenced early scientific thought on Quaternary extinctions and climate; many researchers resorting to catastrophism to explain the instantaneous freezing necessary to preserve palatable meat.

The possibility of cloning is now the major draw of frozen mammoths but the public remains curious about eating prehistoric meat, especially because some modern paleontologists have credibly described tasting mammoth and extinct bison found preserved in permafrost.

Although less publicized today, eating study specimens was once common practice for researchers. Charles Darwin belonged to a club dedicated to tasting exotic meats, and in his first book wrote almost three times as much about dishes like armadillo and tortoise urine than he did on the biogeography of his Galapagos finches.

One of the most famously strange scientific meals occurred on January 13, 1951, at the 47th Explorers Club Annual Dinner (ECAD) when members purportedly dined on frozen woolly mammoth. The prehistoric meat was supposedly found on Akutan Island in Alaska, USA, by the eminent polar explorers Father Bernard Rosecrans Hubbard, “the Glacier Priest,” and Captain George Francis Kosco of the US Navy.

This much-publicized meal captured the public’s imagination and became an enduring legend and source of pride for the Club, popularizing an annual menu of “exotics” that continues today, making the Club as well-known for its notorious hors d’oeuvres like fried tarantulas and goat eyeballs as it is for its notable members such as Teddy Roosevelt and Neil Armstrong.

The Yale Peabody Museum holds a sample of meat preserved from the 1951 meal, interestingly labelled as a South American Giant Ground Sloth, Megatherium, not Mammoth.

Green Sea Turtle, Chelonia mydas

The specimen of meat from that famous meal was originally designated BRCM 16925 before a transfer in 2001 from the Bruce Museum to the Yale Peabody Museum of Natural History (New Haven, CT, USA) where it gained the number YPM MAM 14399.

The specimen is now permanently deposited in the Yale Peabody Museum with the designation YPM HERR 19475 and is accessible to outside researchers. The meat was never fixed in formalin and was initially stored in isopropyl alcohol before being transferred to ethanol when it arrived at the Peabody Museum. DNA extraction occurred at Yale University in a clean room with equipment reserved exclusively for aDNA analyses.

In 2016, Jessica Glass and her colleagues sequenced a fragment of the mitochondrial cytochrome-b gene and studied archival material to verify its identity, which if genuine, would extend the range of Megatherium over 600% and alter views on ground sloth evolution. Their results showed that the meat was not Mammoth or Megatherium, but a bit of Green Sea Turtle, Chelonia mydas. So much for elaborate legends. The prehistoric dinner was likely meant as a publicity stunt. Glass's study emphasizes the value of museums collecting and curating voucher specimens, particularly those used for evidence of extraordinary claims. Not so long before Glass et al. did their experiment, a friend's mother (and my kayaking partners) served up a steak from her freezer to dinner guests in Castlegar that hailed from 1978. Tough? Inedible? I have it on good report that the meat was surprisingly divine.

Reference: Glass, J. R., Davis, M., Walsh, T. J., Sargis, E. J., & Caccone, A. (2016). Was Frozen Mammoth or Giant Ground Sloth Served for Dinner at The Explorers Club?. PloS one, 11(2), e0146825. https://doi.org/10.1371/journal.pone.0146825

SUNSHINE AND SUPERNOVAE

Sunsets — pure visual poetry: peaceful, meditative, mesmerizing.

What is sunlight, actually? Yes, it's light from the Sun but so much more than that. Sunlight is both light and energy. Once it reaches Earth, we call this energy, "insolation," a fancy term for solar radiation. The amount of energy the Sun gives off changes over time in a never-ending cycle.

Solar flares (hotter) and sunspots (cooler) on the Sun's surface impact the amount of radiation headed to Earth. These periods of extra heat or extra cold (well, cold by Sun standards...) can last for weeks, sometimes months. The beams that reach us and warm our skin are electromagnetic waves that bring with them heat and radiation, by-products of the nuclear fusion happening as hydrogen nuclei fuse and shift violently to form helium, a process that fires every star in the sky.

Our bodies convert the ultraviolet rays to Vitamin D. Plants use the rays for photosynthesis, a process of converting carbon dioxide to sugar and using it to power their growth (and clean our atmosphere!) That process looks something like this: carbon dioxide + water + light energy — and glucose + oxygen = 6 CO2(g) + 6 H2O + photons → C6H12O6(aq) + 6 O2(g).

Photosynthetic organisms convert about 100–115 thousand million metric tonnes of carbon to biomass each year, about six times more power than used us mighty homo sapien sapiens. Our plants, forests and algae soak up this goodness and much later in time, we harvest this energy from fossil fuels.

We've yet to truly get a handle on the duality between light as waves and light as photons. The duality of the two-in-oneness of light; of their waves and alter-ego, particle photons is a physicists delight. Einstein formulated his special theory of relativity in part by thinking about what it would be like to ride around on these waves. What would space look and feel like? How would time occur? It bends the mind to consider. His wave-particle view helped us to understand that these seemingly different forms change when measured. To put this in plain English, they change when viewed, ie. you look them "in the eye" and they behave as you see them.

Light fills not just our wee bit of the Universe but the cosmos as well, bathing it in the form of cosmic background radiation that is the signature of the Big Bang and the many mini-big bangs of supernovae as they go through cycles of reincarnation and cataclysmic death — exploding outward and shining brighter than a billion stars.

In our solar system, once those electromagnetic waves leave the Sun headed for Earth, they reach us in a surprising eight minutes. We experience them as light mixed with the prism of beautiful colours. But what we see is actually a trick of the light. As rays of white sunlight travel through the atmosphere they collide with airborne particles and water droplets causing the rays to scatter.

We see mostly the yellow, orange and red hues (the longer wavelengths) as the blues and greens (the shorter wavelengths) scatter more easily and get bounced out of the game rather early.

HOLDERNESS AMMONITE

An unusual Yorkshire Holderness ammonite about 5cm across found by Harry Tabiner. He’s found a few of these specimens preserved completely with calcite making them hard to prepare. It’s possibly Kosmoceras, a middle Jurassic ammonite.

The Geology of Yorkshire in northern England shows a very close relationship between the major topographical areas and the geological period in which their rocks were formed. The rocks of the Pennine chain of hills in the west are of Carboniferous origin whilst those of the central vale are Permo-Triassic.

The North York Moors in the north-east of the county are Jurassic in age while the Yorkshire Wolds to the southeast are Cretaceous chalk uplands. The plain of Holderness and the Humberhead levels both owe their present form to the Quaternary ice ages. The strata become gradually younger from west to east. Much of Yorkshire presents heavily glaciated scenery as few places escaped the direct or indirect impact of the great ice sheets as they first advanced and then retreated during the last ice age. This beauty is in the collection of the deeply awesome Harry Tabiner.

CORAL: CLIMATE CHANGE INDICATORS

A lovely specimen of fossilized coral. Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically live in compact colonies of many identical individual polyps.

Annual growth bands in some corals, such as the deep-sea bamboo coral, Isididae, may be among the first signs of the effects of ocean acidification on marine life. The growth rings allow geologists to construct year-by-year chronologies, a form of incremental dating, which underlies high-resolution records of past climatic and environmental changes using geochemical techniques.

Certain species form communities called microatolls, which are colonies whose top is dead and mostly above the waterline, but whose perimeter is mostly submerged and alive. The average tide level limits their height. By analyzing the various growth morphologies, microatolls offer a low-resolution record of sea-level change. Fossilized microatolls can also be dated using Radiocarbon dating. Such methods can help to reconstruct Holocene sea levels.

Increasing sea temperatures in tropical regions, ~1 degree C, over the last century have caused major coral bleaching, death, and collapsing of coral populations since although they are able to adapt and acclimate. It is uncertain if this evolutionary process will happen quickly enough to prevent a major reduction of their numbers.

Though coral has large sexually-reproducing populations, their evolution can be slowed by abundant asexual reproduction. Gene flow is variable among coral species. According to the biogeography of coral species gene flow cannot be counted on as a dependable source of adaptation as they are very stationary organisms. Also, coral longevity might factor into their adaptivity.

However, adaptation to climate change has been demonstrated in many cases. These are usually due to a shift in coral and zooxanthellae genotypes. These shifts in allele frequency have progressed toward more tolerant types of zooxanthellae. Scientists found that a certain scleractinian zooxanthella is becoming more common where sea temperature is high. Symbionts able to tolerate warmer water seem to photosynthesize more slowly, implying an evolutionary trade-off.

In the Gulf of Mexico, where sea temperatures are rising, cold-sensitive staghorn and elkhorn coral have shifted in location. Not only have the symbionts and specific species been shown to shift, but there seems to be a certain growth rate favorable to selection. Slower-growing but more heat-tolerant corals have become more common. The changes in temperature and acclimation are complex. Some reefs in current shadows represent a refugium location that will help them adjust to the disparity in the environment even if eventually the temperatures may rise more quickly there than in other locations. This separation of populations by climatic barriers causes a realized niche to shrink greatly in comparison to the old fundamental niche.

CORAL COLONIES

Coral colony and Soldier Fish, Great Barrier Reef, Australia

Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically live in compact colonies of many identical individual polyps.

Corals are important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.

A coral "group" is a colony of a myriad of genetically identical polyps. Each polyp is a sac-like animal typically only a few millimetres in diameter and a few centimetres in length. A set of tentacles surround a central mouth opening. Each polyp excretes an exoskeleton near the base. Over many generations, the colony thus creates a skeleton characteristic of the species which can measure up to several meters in size. Individual colonies grow by asexual reproduction of polyps. Corals also breed sexually by spawning: polyps of the same species release gametes simultaneously overnight, often around a full moon. Fertilized eggs form planulae, a mobile early form of the coral polyp which when mature settles to form a new colony.

Although some corals are able to catch plankton and small fish using stinging cells on their tentacles, most corals obtain the majority of their energy and nutrients from photosynthetic unicellular dinoflagellates of the genus Symbiodinium that live within their tissues. These are commonly known as zooxanthellae and gives the coral colour. Such corals require sunlight and grow in clear, shallow water, typically at depths less than 60 metres (200 ft). Corals are major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters, such as the Great Barrier Reef off the coast of Australia. These corals are increasingly at risk of bleaching events where polyps expel the zooxanthellae in response to stress such as high water temperature or toxins.

Other corals do not rely on zooxanthellae and can live globally in much deeper water, such as the cold-water genus Lophelia which can survive as deep as 3,300 metres (10,800 ft). Some have been found as far north as the Darwin Mounds, northwest of Cape Wrath, Scotland, and others off the coast of Washington State and the Aleutian Islands.

TUZOIA OF THE BALANG FORMATION

A large extinct bivalved arthropod, Tuzoia sinesis (Pan, 1957) from Cambrian deposits of the Balang Formation. The Balang outcrops in beautiful Paiwu, northwestern Hunan Province in southern China. The site is intermediate in age between the Lower Cambrian Chengjiang fauna of Yunnan and the Lower to Middle Cambrian, Kaili Lagerstätten of Guizhou in southwestern China.

This specimen was collected in October 2019. It is one of many new and exciting arthropods to come from the site. Balang has a low diversity of trilobites and many soft-bodied fossils similar in preservation to Canada's Burgess Shale.

Some of the most interesting finds include the first discovery of anomalocaridid appendages (Appendage-F-type) from China along with the early arthropod Leanchoiliids with his atypical frontal appendages (and questionable phylogenetic placement) and the soft-shelled trilobite-like arthropod, Naraoiidae.

Jianheaspis jiaobangensis, is a newly described trilobite also from the Lower Cambrian Balang Formation of Guizhou Province, China. While the site is not as well-studied as the Chengjiang and Kaili Lagerstätten, it looks very promising. The exceptionally well-preserved fauna includes algae, sponges, chancelloriids, cnidarians, worms, molluscs, brachiopods, trilobites and a few non-mineralized arthropods. It is an exciting time for Cambrian paleontology. The Balang provides an intriguing new window into our ancient seas and the profound diversification of life that flourished there.

ZEACINITIES MAGNOLIAEFORMIS

This lovely specimen is Zeacrinites magnoliaeformis, an Upper Mississippian-Chesterian crinoid found by Keith Metts in the Glen Dean Formation, Grayson County, Kentucky, USA.

Crinoids are unusually beautiful and graceful members of the phylum Echinodermata. They resemble an underwater flower swaying in an ocean current. But make no mistake they are marine animals. Picture a flower with a mouth on the top surface that is surrounded by feeding arms. Awkwardly, add an anus right beside that mouth. That's him!

Crinoids with root-like anchors are called Sea Lilies. They have graceful stalks that grip the ocean floor. Those in deeper water have longish stalks up to 3.3 ft or a meter in length.

Then there are other varieties that are free-swimming with only vestigial stalks. They make up the majority of this group and are commonly known as feather stars or comatulids. Unlike the sea lilies, the feather stars can move about on tiny hook-like structures called cirri. It is these same cirri that allows crinoids to latch to surfaces on the seafloor. Like other echinoderms, crinoids have pentaradial symmetry. The aboral surface of the body is studded with plates of calcium carbonate, forming an endoskeleton similar to that in starfish and sea urchins.

These make the calyx somewhat cup-shaped, and there are few, if any, ossicles in the oral (upper) surface called a tegmen. It is divided into five ambulacral areas, including a deep groove from which the tube feet project, and five interambulacral areas between them. The anus, unusually for echinoderms, is found on the same surface as the mouth, at the edge of the tegmen.

Crinoids are alive and well today. They are also some of the oldest fossils on the planet. We have lovely fossil specimens dating back to the Ordovician.

PHYLLOCERAS PONTICULI DE CORDOBA

Phylloceras (Hypophylloceras) ponticuli from the Subbético Externo de Córdoba, a fast-moving carnivorous ammonite. This classical Tethyan Mediterranean specimen is very well preserved, showing much of his delicate suturing in intricate detail. Phylloceras were primitive ammonites with involute, laterally flattened shells.

They were smooth, with very little ornamentation, which led researchers to think of them resembling plant leaves and gave rise to their name, which means leaf-horn. They can be found in three regions that I know of.  In the Jurassic of Italy near western Sicily's Rosso Ammonitico Formation, Lower Kimmeridgian fossiliferous beds of Monte Inici East and Castello Inici (38.0° N, 12.9° E: 26.7° N, 15.4° E) and in the Arimine area, southeastern Toyama Prefecture, northern central Japan, roughly, 36.5° N, 137.5° E: 43.6° N, 140.6° E. And in Madagascar, in the example seen here found near Sokoja, Madagascar, off the southeast coast of Africa at 22.8° S, 44.4° E: 28.5° S, 18.2° E. Photo: Manuel Peña Nieto

PHYLLOCERAS VELLEDAE

This specimen of Phylloceras velledae (Michelin) has a shell with a small umbilicus, arched, acute venter, and at some growth stage, falcoid ribs that spring in pairs from umbilical tubercles, disappearing on the outer whorls.

This specimen has been polished to show the sutures to great effect. These ammonites are common in rock shops and plentiful on the internet.

These ammonites make a lovely addition to any teaching collection as they provide a lot of detail and can be handled quite well by small, less gentle hands. Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. They used these tentacles to snare prey, — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunt today.

Catching a fish with your hands is no easy feat, as I'm sure you know. But the Ammonites were skilled and successful hunters. They caught their prey while swimming and floating in the water column. Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube. By pushing air in or out, they were able to control their buoyancy in the water column.

They lived in the last chamber of their shells, continuously building new shell material as they grew. As each new chamber was added, the squid-like body of the ammonite would move down to occupy the final outside chamber.

They were a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids — octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living Nautilus species.

LENS ON SEPTARIAN NODULES

Septarian Nodule, Dan Bowen, 2020 Tucson Gem and Mineral Show

An exceptional polished septarian nodule with an ammonite heart. Septarian concretions or septarian nodules are concretions containing angular cavities or cracks, called "septaria." These septaria can be filled 

The word comes from the Latin word septum; "partition", and refers to the cracks/separations in this kind of rock.

The process that created the septaria that characterize septarian concretions remains unclear. A number of mechanisms have been proposed, including the dehydration of clay-rich, gel-rich, or organic-rich cores; shrinkage of the concretion's center; expansion of gases produced by the decay of organic matter; or brittle fracturing or shrinkage of the concretion interior by either earthquakes or compaction.

The cracks or patterns you see here are highly variable in shape and volume, as well as the degree of shrinkage they indicate. Although it has commonly been assumed that concretions grew incrementally from the inside outwards, the fact that radially oriented cracks taper towards the margins of septarian concretions is taken as evidence that in these cases the periphery was stiffer while the inside was softer, presumably due to a gradient in the amount of cement precipitated.

A spectacular example of septarian concretions, which are as much as 3 meters (9.8 feet) in diameter, are the Moeraki Boulders. These concretions are found eroding out of Paleocene mudstone of the Moeraki Formation exposed along the coast near Moeraki, South Island, New Zealand. They are composed of calcite-cemented mud with septarian veins of calcite and rare late-stage quartz and ferrous dolomite.

Beautiful smaller septarian concretions are found in the Kimmeridge Clay exposed in cliffs along the Wessex Coast of England. As as you walk the beach, look for exposures of Speeton Clay beds D6 and D7, the bentonite horizons that weather to yellow colouration. Beneath the Speeton Shell Bed cliff exposures is an exposure of Kimmeridge Clay, UK. This outcrop contains concretions that show the characteristic 'turtle-stone' patterns of these septarian nodules.

Photo top: Dan Bowen, Chair, VIPS, 2020 Tucson Gem and Mineral Show.

References: Humberside Geologist No. 14, Humberside Geologist Online, The geology of East Yorkshire coast.http://www.hullgeolsoc.co.uk/hg146t.htm

Dale, P.; Landis, C. A.; Boles, J. R. (1985-05-01). "The Moeraki Boulders; anatomy of some septarian concretions". Journal of Sedimentary Research. 55 (3): 398–406.

Milliken, Kitty L.; Picard, M. Dane; McBride, Earle F. (2003-05-01). "Calcite-Cemented Concretions in Cretaceous Sandstone, Wyoming and Utah, U.S.A." Journal of Sedimentary Research. 73 (3): 462–483. Bibcode:2003JSedR..73..462M. doi:10.1306/111602730462. ISSN 1527-1404.

AMMONITES: INDEX FOSSILS

Ammonites were prolific breeders that evolved rapidly. If you could cast a fishing line into our ancient seas, it is likely that you would hook an ammonite, not a fish. They were prolific back in the day, living (and sometimes dying) in schools in oceans around the globe.

We find their fossilized remains (and plenty of them) in sedimentary rock from all over the world. In some cases, we find rock beds where we can see evidence of a new species that evolved, lived and died out in such a short time span that we can walk through time, following the course of evolution using ammonites as a window into the past. For this reason, they make excellent index fossils.

An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. Generally, deeper is older, so we use the sedimentary layers rock to match up to specific geologic time periods, rather the way we use tree-rings to date trees. Photo: Dan Bowen, 2020 Tucson Gem and Mineral Show.

HOLCOPHYLLOCERAS MEDITERRANEUM

There is tremendously robust suturing on this lovely ammonite, Holcophylloceras mediterraneum, (Neumayr 1871) from Late Jurassic (Oxfordian) deposits near Sokoja, Madagasgar.

They were a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids — octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living Nautilus species.

Ammonites first appeared about 240 million years ago, though they descended from straight-shelled cephalopods called bacrites that date back to the Devonian, about 415 million years ago, and the last species vanished in the Cretaceous–Paleogene extinction event.

The shells had many chambers divided by walls called septa. The chambers were connected by a tube called a siphuncle which allowed for the control of buoyancy with the hollow inner chambers of the shell acting as air tanks to help them float. We can see the edges of this specimen's shell where it would have continued out to the last chamber, the body chamber, where the ammonite lived. Picture a squid or octopus, now add a shell and a ton of water.

ANDROGYNOCERAS OF YORKSHIRE

A stunning example of the ammonite Androgynoceras from the Yorkshire Coast, England.

The Geology of Yorkshire in northern England shows a very close relationship between the major topographical areas and the geological period in which their rocks were formed. The rocks of the Pennine chain of hills in the west are of Carboniferous origin whilst those of the central vale is Permo-Triassic.

The North York Moors in the north-east of the county are Jurassic in age while the Yorkshire Wolds to the southeast are Cretaceous chalk uplands.

The plain of Holderness and the Humberhead levels both owe their present form to the Quaternary ice ages. The strata become gradually younger from west to east. Much of Yorkshire presents heavily glaciated scenery as few places escaped the direct or indirect impact of the great ice sheets as they first advanced and then retreated during the last ice age. This beauty is in the collection of the deeply awesome Harry Tabiner.

MIDDLE TRIASSIC HUMBOLDT RANGE

Looking out over the Middle Triassic exposures of the Humboldt Mountain Range.

These hills were the site of the 1905 Expedition of the University of California’s Department of Geology in Berkeley funded by the beautiful and bold, Annie Alexander, the women to whom the UCMP owes both its collection and existence. Annie brought together a paleontological crew to explore these localities and kept an expedition journal of their trip which is now on display at the University of California Museum of Paleontology at Berkeley.

Annie's interest was the ichthyosaurs and she was well pleased with the results. They dodged rattlesnakes and tarantulas, finding many new specimens as they opened up new quarries in the hills of the Humboldt Range of Nevada.

Ichthyosaurs range from quite small, just a foot or two, to well over twenty-six metres in length and resembled both modern fish and dolphins. The specimens from Nevada are especially large and well-preserved. They hail from a time, some 217 million years ago, when Nevada, and parts of the western USA, was covered by an ancient ocean that would one day become our Pacific Ocean. Many ichthyosaur specimens have come out of Nevada. So many, in fact, that they named it their State Fossil back in 1977.

Fossil fragments and complete specimens of these marine reptiles have been collected in the Blue Lias near Lyme Regis and the Black Ven Marls. More recently, specimens have been collected from the higher succession near Seatown. Paddy Howe, Lyme Regis Museum geologist, found a rather nice Ichthyosaurus breviceps skull a few years back. A landslip in 2008 unveiled some ribs poking out of the Church cliffs and a bit of digging revealed the ninth fossil skull ever found of a breviceps, with teeth and paddles to boot.

Specimens have since been found in Europe in Belgium, England, Germany, Switzerland and in Indonesia. Many tremendously well-preserved specimens come from the limestone quarries in Holzmaden, southern Germany.

AMMONITE: INDEX FOSSILS

Ammonites first appeared about 240 million years ago, though they descended from straight-shelled cephalopods called bacrites that date back to the Devonian, about 415 million years ago, and the last species vanished in the Cretaceous–Paleogene extinction event.

They were prolific breeders that evolved rapidly. If you could cast a fishing line into our ancient seas, it is likely that you would hook an ammonite, not a fish. They were prolific back in the day, living — and sometimes dying — in schools in oceans around the globe. We find ammonite fossils — and plenty of them — in sedimentary rock from all over the world. In some cases, we find rock beds where we can see evidence of a new species that evolved, lived and died out in such a short time span that we can walk through time, following the course of evolution using ammonites as a window into the past.

For this reason, they make excellent index fossils. An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. Generally, deeper is older, so we use the sedimentary layers rock to match up to specific geologic time periods, rather the way we use tree-rings to date trees. A handy way to compare fossils and date strata across the globe.

UPPER CRETACEOUS NANAIMO GROUP AT HORNBY ISLAND

Hornby is a delightful island off the east coast of Vancouver Island, just east of Denman Island. Texada and Lasqueti lie just to the west of Hornby. It is home to about 1,000 residents made up of artists, retirees and those wanting to enjoy the quiet, rural, community-oriented lifestyle.

Hornby Island is formed from sediments of the upper Nanaimo Group which are also widely exposed on adjacent Denman Island and the southern Gulf Islands. Peter Mustard, a geologist from the Geologic Survey of Canada, did considerable work on the geology of the island. It has a total stratigraphic thickness of 1350 m of upper Nanaimo Group marine sandstone, conglomerate and shale.

These are partially exposed in the Campanian to the lower Maastrichtian outcrops at Collishaw Point on the northwest side of Hornby Island. Four formations underlie the island from oldest to youngest, and from west to east: the Northumberland, Geoffrey, Spray and Gabriola.

During the upper Cretaceous, between ~90 to 65 Ma, sediments derived from the Coast Belt to the east and the Cascades to the southeast poured seaward to the west and northwest into what was the large ancestral Georgia Basin. This major forearc basin was situated between Vancouver Island and the mainland of British Columbia.

The island's soils have developed from marine deposits of variable texture, except for the higher elevations and steeper slopes where weathered clastic sedimentary rock provides the parent material. Most of Hornby's soils are sandy or gravelly, but some deep black loams occur in the northwestern part and many of the sands at the southern end have loam-textured topsoils.

Collishaw Point, known locally as Boulder Point, Hornby Island

Podzols are common and the bleached sand grains associated with their eluvial (A2, Ae or E) horizons lend a salt-and-pepper appearance to many forest trails. In most cases, though, the E is not very thick and may, in fact, be discontinuous. For this reason, the soils were mostly classified as Brown Podzolic in a soil survey published in 1959.

All of the island's soils are strongly acidic in their natural state except for those which have developed on shoreline shell middens.

And it is to the shore that many are drawn — locals, tourists, geologists and paleontologists alike. Hornby is a wonderful place to explore. The island is beautiful in its own right and the fossils from here often keep some of their original shell or nacre which makes them quite fetching.

The Nanaimo Group as a whole represents largely coarse-grained units deposited in deep-sea fan systems. In this environment, deeper channels continuously cut through successive shale and sandstone bodies. The channels funnelled density currents into the basin, while also building levee deposits. Turbidity currents travelled down the channels, and also overtopped the levees spilling across backslope areas. The sequential sediment formations, from significantly coarse-grained sandstones and conglomerates to fine silts and shale units of the Nanaimo Group, are considered to be partly due to eustacy, but more significantly related to relative sea-level changes induced by regional tectonics in an active forearc setting.

The Northumberland Formation consists of a massive, dark-grey mudstone which is locally interlaminated and interbedded with siltstone and fine-grained sandstone.

There are abundant calcium carbonate concretions, parallel and current ripple laminations, clastic dikes and folded layers due to slumping. In the Gulf Islands to the south, this formation has been found to contain abundant and diverse foraminifera indicating marine paleodepths of 150-1200 m.

The more resistive Geoffrey Formation consists of thick-bedded sandstone and conglomerate. It is highly channelized, and some sandstone has exposed parallel and ripple laminations. The Spray Fm exposed on the east end of the island is a massive olive-grey mudstone with interlaminations of sandstone.

Furthest to the east, the youngest exposures on Hornby Island are from the Gabriola Formation, which outcrops on the eastern peninsula. This is again a thick-bedded and channelized sequence of conglomerates and massive sandstone with minor mudstone interbeds. South, in the Gulf Islands, this formation has contained ammonites, gastropods and pelecypods. Paleowater-depth from foraminiferal assemblages has been set at 200 m.

Katnick, D.C. and P.S. Mustard (2001): Geology of Denman and Hornby Islands, British Columbia (NTS 92F/7E, 10); British Columbia Geological Survey Branch, Geoscience Map 2001-3.

England, T.D.J. and R. N. Hiscott (1991): Upper Nanaimo Group and younger strata, outer Gulf Islands, southwestern British Columbia: in Current Research, Part E; Geological Survey of Canada, Paper 91-1E, p. 117-125.