Monday 20 September 2021
SHORT-BEAKED ECHIDNA
Sunday 19 September 2021
OKANAGAN HIGHLAND LOCALITIES OF BRITISH COLUMBIA
Friday 17 September 2021
FOSSIL SEED FERN
They are members of the Order Medullosales — closely related to modern-day cycads.
These extinct ferns lived 310 million years ago during the Great Coal Age — a timeframe that includes the Pennsylvanian and Mississippian periods when much of the Earth's coal was formed.
As ferns, trees and other plant matter decayed, vast deposits of peat accumulated. Floodwaters brought silt deposits, covering and intermingling with the decaying peat. Time and pressure turned that mixture to the coal we mine today.
Back when they were alive, Pennsylvania was largely a tropical swamp with ferns towering at more than 50 feet high. They dominated the landscape, lived and died a full 185 million years before the first of our lovely flowering plants had even arrived.
Thursday 16 September 2021
NORTH SEA DOLPHIN VERTEBRAE: HATSAWE'
Bottlenose dolphins first appeared during the Miocene and swam the shallow seas of this region.
We still find them today in warm and temperate seas worldwide though unlike narwhal, beluga and bowhead whales, Bottlenose dolphins avoid the Arctic and Antarctic Circle regions.
Their name derives from the Latin tursio (dolphin) and truncatus for their characteristic truncated teeth. In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest — and part of my heritage — dolphin are hatsawe'.
On the north end of Vancouver Island, we have pods of 50-100 Pacific White-Sided dolphins, cousins of the Bottlenose, who frolic and jump alongside your boat if you are out on the water. Similar to their southern cousins, Pacific White-Sided dolphins feed on salmon, herring, pilchards, anchovies, needlefish, squid, shrimp, pollock, sablefish, rock cod and other small fish — a tasty menu that reflects my own.
Bottlenose dolphins are the most common dolphin species in the Pacific Northwest but do not often venture farther north than Oregon. We have two populations of bottlenose dolphins here, the California coastal population and those that prefer to live offshore. It is as exciting to see them playing in our oceans today as it is to see the fossil remains of their ancestors from the Brown Bank sediments of the North Sea.
Brown Bank, North Sea, Pleistocene Dredging Area |
Many waterworn vertebrae from the Harbour Porpoise Phocoena sp., (Cuvier, 1816), Bottlenose dolphin Tursiops sp. (Gervais, 1855), and Beluga Whale, Delphinapterus sp. (Lacépède, 1804) are found by fishermen as they dredge the bottom of the Brown Bank, one of the deepest sections of the North Sea.
The North Sea is a sea of the Atlantic Ocean located between the United Kingdom, Denmark, Norway, Germany, the Netherlands, Belgium and France. An epeiric sea on the European continental shelf, it connects to the ocean through the English Channel in the south and the Norwegian Sea in the north.
The fishermen use small mesh trawl nets that tend to scoop up harder bits from the bottom. This technique is one of the only ways this Pleistocene and other more recent material is recovered from the seabed, making them relatively uncommon. The most profitable region for fossil mammal material is in the Brown Bank area of the North Sea. I have circled this area on the map below to give you an idea of the region.
Found by Fishermen in the North Sea. Using a small mesh trawl net is often the only time these come up from the seabed, hence they are uncommon. Size: 17.0cm. Age: 30-40,000 Years old.
Wednesday 15 September 2021
FISHING IN ANCIENT SEAS
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 of rock to match up to specific geologic time periods, rather like the way we use tree rings to date trees.
Monday 13 September 2021
FOSSIL FAUNA OF HAIDA GWAII
This specimen is just over 12cm in length, a little under the average of 13.4cm. There are several localities in the islands of Haida Gwaii where Brewericeras can be found — six that I know of and likely plenty more.
The islands of Haida Gwaii lay at the western edge of the continental shelf due west of the central coast of British Columbia.
They form Wrangellia, an exotic tectonostratigraphic terrane that includes Vancouver Island, parts of western British Columbia and Alaska.
It is always interesting to see who was making a living and co-existing in our ancient oceans at the time these fossils were laid down.
We find multiple beautifully preserved specimens of the spiny ammonite, Douvelleiceras spiniferum along with Brewericeras hulenense (shown here), Cleoniceras perezianum and many cycads in concretion.The Lower Jurassic ammonite faunas found at Haida Gwaii are very similar to those found in the Eastern Pacific around South America and in the Mediterranean.
The strata exposed at Maple Island, Haida Gwaii are stratigraphically higher than the majority of Albian localities in Skidegate Inlet. The macrofossil fauna belonged to the Upper part of the Sandstone Member of the Haida formation.
The western end of the island contains numerous well-preserved inoceramids such as Birostrina concentrica and a few rare ammonites of Desmoceras bearskinese.
The eastern shores are home to unusual ammonite fauna in the finer-grained sandstones. Here we find the fossils as extremely hard concretions while others were loose in the shale. Species include Anagaudryceras sacya and Tetragonites subtimotheanus. A large whorl section of the rare Ammonoceratites crenucostatus has also been found here.
Saturday 11 September 2021
STYXOSAURUS: ELASMO-TERROR OF ANCIENT SEAS
Styxosaurus, one of the large plesiosaurs in the family Elasmosauridae, takes on a giant octopus.
Styxosaurus was an elasmosaur that appeared in the Late Cretaceous.
The holotype specimen of Styxosaurus snowii was described by S.W. Williston from a complete skull and 20 vertebrae. Elasmosaurs typically have a neck that is at least half the length of the body, composed of 60-72 vertebrae.
They were very successful hunters, outcompeting ichthyosaurs who thrived in the Triassic but were replaced in the Jurassic and Cretaceous by these new aquatic beasties.
Our ancient seas teemed with these predatory marine reptiles with their long necks and barrel-shaped bodies. Styxosaurus was around 11 metres (36 ft) long — and true to its family Elasmosauridae — about half of the length being composed of its 5.25 metres (17.2 ft) neck. Its sharp teeth were conical and were adapted to puncture and hold rather than to cut; like other plesiosaurs.
Styxosaurus preferred to gulp down their food whole. They may have taken bits and pieces of a giant octopus similar to the one depicted but would have likely preferred a smaller prey that could be swallowed in one go.
Friday 10 September 2021
ANCIENT MARINE PREDATORS: PLESIOSAURS
We see them arise in the fossil record some 203 million years ago and then go extinct 66 million years ago.
We had originally thought that this might not be the most aerodynamic design but it was clearly effective as they used the extra set to create a wee vortex that aided in their propulsion.
In terms of mechanical design, they have a little something in common with an unlikely favourite of mine — dragonflies.
We have recreated plesiosaur movements and discovered that they were able to optimize propulsion to make use of their own wake. As their front flippers paddled in big circular movements, the propelled water created little whirlpools under their bellies. The back flippers would then paddle between these whirlpools pushing the plesiosaur forward to maximal effect. This use of air currents is similar to how dragonflies move through the air.
They were very successful hunters, outcompeting ichthyosaurs who thrived in the Triassic but were replaced in the Jurassic and Cretaceous by these new aquatic beasties.
Our ancient seas teemed with these predatory marine reptiles with their long necks and barrel-shaped bodies. Plesiosaurs were smaller than their pliosaur cousins, weighing in at about 450 kg or 1,000 lbs and reaching about 4.5 metres or 15 feet in length. For a modern comparison, they were roughly twice as long as a standard horse or about as long as a good size hippo.
Thursday 9 September 2021
CANADOCERAS YOKOYAMAI: HASLAM FORMATION
This meaty cephalopod swam and hunted in our ancient oceans 80-84 million years ago and was once a leading candidate as the provincial fossil of British Columbia — an honour won by Shonisaurus sikanniensis.
The species is named for Matajirō Yokoyama, Professor of Geology and Palaeontology at the Imperial University of Tokyo, Japan.
Yokoyama was born in the Nagasaki Prefecture on the 14th of June 1860 — the day slavery was abolished in the Neth Indies and the year Abraham Lincoln was elected president of the United States — a move that would lead to the beginning of the US Civil War the following year.
During his early life, the Meiji Restoration would begin the process of transforming Japan into a global imperial power. During the Restoration, Japan rapidly industrialized, adopting Western ideas and production methods. This shift in the cultural focus of his nation allowed him to pursue his studies in science — something encouraged in an emerging nation.
Matajirō Yokoyama (1860-1942) |
References:
Matsumoto, T., 1954a [for 1953]: The Cretaceous system in the Japanese islands., pp. i–xiv + 1–324, pls. 1–20. The Japanese Society for the Promotion of Scientific Research, Ueno, Tokyo. (Reference No. 0219)
Tanabe, K., Ito, Y., Moriya, K. and Sasaki, T., 2000: Database of Cretaceous ammonite specimens registered in the Department of Historical Geology and Paleontology of the University Museum, University of Tokyo. The University Museum, The University of Tokyo, Material Reports, no. 37, pp. i–iv + 1–509. (Reference No. 0879)
Photo: Matajirō Yokoyama, Professor of Geology, Palaeontology and Mineralogy. 日本語: 横山又次郎 地質学古生物学及鉱物学教授 Tokyo Teikoku Daigaku (Imperial University of Tokyo). Ogawa Shashin Seihanjo, 1900 (reprint, Ryūkei Shosha, 2004).
Wednesday 8 September 2021
OCEAN SUNFISH: MOLA MOLA
Mola mola (Linnaeus, 1758) |
The sheer size and thick skin of an adult of the species deter many smaller predators, but younger fish are vulnerable to predation by bluefin tuna and mahi-mahi.
Tuesday 7 September 2021
PHRAGMOTEUTHIS CONOCAUDA
Phragmoteuthis conocauda |
Phragmoteuthis is a genus of extinct coleoid cephalopod known from the late Triassic to the Lower Jurassic. Its soft tissue has been preserved wonderfully. Some rare specimens contain intact ink sacs, arm hooks, and others, gills.
There are some wonderful specimens from the Carnian, Late Triassic outcrops near Lunz, in Lower Austria with wee arm hooks and ink sacs, though the ink now looks like an agglomerate of grains.
In Toarcian deposits in Southwestern Germany, we find fragments of Phracmoteuthis concocauda with bits of gill preserved. They look remarkably like the gills of octopod and vampyromorph colcoids.
Palaeontologist Jurji (Jura) Jeletzky characterized phragmoteuthids as having a large tripartite, fanlike pro-ostracum forming the longest portion of the shell, attached to about three-quarters of the circumference of a comparatively small breviconic phragmocone with short camerae and superficially belemnitid-like siphuncle.
Add that to an absent or much-reduced rostrum at the apical part of the phragmocone, belemnite-like arm hooks, an ink sack, beaks resembling those of recent teuthids, and a muscular mantle.
Think early squid. These are their great great grandparents.
This specimen is in the collections of the University of Oslo Natural History Museum, Norway's oldest and largest museum of natural history in the lovely neighbourhood of Tøyen near Grünerløkka in Oslo. If you visit, check out the nearby Munch Museum to see some of Edvard Munch's work.
Monday 6 September 2021
Sunday 5 September 2021
FIRST NATION POLES IN STANLEY PARK
Totem, Welcome & Mortuary Poles at Stanley Park |
What you are viewing are replicas of First Nation welcome and totem poles that once stood in the park but have been returned to their homes within the province's diverse First Nation communities — or held within museum collections.
Some of the original totems came from Alert Bay on Cormorant Island, near the Port McNeill on the north coast of Vancouver Island. Others came from communities in Haida Gwaii — and still more from the Wuikinuxv First Nations at Rivers Inlet on British Columbia's central west coast — home of the Great Bear Rainforest with her Spirit Bears.
The exception is the most recent addition carved by Robert Yelton in 2009. Robert is a First Nation carver from the Squamish Nation and his original welcome pole graces Brockton Point, the original settlement site of a group of Squamish-Portuguese settlers.
If you look at the photo above, the lovely chocolate, red and turquoise pole on the right is a replica of the mortuary pole raised to honour the Raven Chief of Skedans or Gida'nsta, the Haida phrase for from his daughter, the title of respect used when addressing a person of high rank. Early fur traders often took the name of the local Chief and used it synonymously as the place names for the sites they visited — hence Skedans from Gida'nsta.
Chief Skedans Mortuary Pole |
Upon Chief Skedan's death, the mortuary pole was carved both to honour him and provide his final resting place. Dates are a bit fuzzy, but local accounts have this as sometime between 1870-1878 — and at a cost of 290 blankets or roughly $600 in today's currency.
The great artistry of the pole was much admired by those in the community and those organizing the celebrations for the 1936 Vancouver Golden Jubilee — witnessed by 350,000 newly arrived residents.
Negotiations were pursued and the pole made its way down from Haida Gwaii to Stanley Park in time for the celebrations. The original totem graced Stanley Park for a little over twenty years before eventually making its way back to Haida Gwaii. It was returned to the community with bits of plaster and shoddy paint marring the original. These bits were scraped off and the pole welcomed back with due ceremony.
In 1964, respected and renowned Northwest Coast master carver, Bill Reid, from the Kaadaas gaah Kiiguwaay, Raven/Wolf Clan of T'anuu, Haida Gwaii and Scottish-German descent, was asked to carve this colourful replica.
Mountain Goat Detail, Skedans Mortuary Pole |
Don Yeomans, Haida master carver, meticulously recarved the moon crest in 1998. If you have admired the totem pole in the Vancouver Airport, you will have seen some of Yeoman's incredible work.
The crest is Moon with the face, wings, legs and claws of a mighty and proud Thunderbird with a fairly smallish hooked beak in a split design. We have Moon to thank for the tides and illuminating our darkest nights. As a crest, Moon is associated with transformation and acting as both guardian and protector.
The original pole had a mortuary box that held the Chief's remains. The crest sits atop a very charming mountain goat. I have included a nice close-up here of the replica for you to enjoy.
Mountain Goats live in the high peaks of British Columbia and being so close to the sky, they have the supernatural ability to cross over to the sky world. They are also credited as being spirit guardians and guides to First Nation shamans.
I love his horns and tucked in cloven hooves. There is another pole being carved on Vancouver Island that I hope to see during its creation that also depicts a Mountain Goat. With permission and in time, I hope to share some of those photos with you.
Mountain Goat is sitting atop Grizzly Bear or Huaji or Xhuwaji’ with little human figures placed in his ears to represent the Chief's daughter and son-in-law, who raised the pole and held a potlatch in his honour.
Beneath the great bear is Seal or Killer Whale in his grasp. The inscription in the park says it is a Killer Whale but I am not sure about that interpretation — both the look and lore make Seal more likely. Perhaps if Killer Whale were within Thunderbird's grasp — maybe.
Though it is always a pleasure to see Killer Whale carved in red cedar, as the first whales came into being when they were carved in wood by a human — or by Raven — then magically infused with the gift of life.
Siwash Rock on the northern end of Third Beach, Stanley Park |
Glacial deposits sit atop as a mix of clay, sand, cobbles and larger boulders of glacial till.
There are a few areas of exposed volcanics within the park that speak to the scraping of the glaciers as they retreated about 12,500 years ago.
The iconic moss and lichen coated Siwash Rock on the northern end of Third Beach is one of the more picturesque of these. It is a basaltic and andesitic volcanic rock — a blend of black phenocrysts of augite cemented together with plagioclase, hornblende and volcanic glass.
Images not shown:
Do check out the work of Emily Carr and her paintings of Q:o'na from the 1940s. I'll share a link here but do not have permission to post her works. http://www.emilycarr.org/totems/exhibit/haida/ssintro.htm
Saturday 4 September 2021
STANLEY PARK: HIDDEN HISTORY
Anavitrinella pampinaria / Dan Bowden Photography |
Brockton Point. City of Vancouver Archives, CVA 677-228 |
The thin, greyish-brown and scaly bark provides a pretty good cover. He was caught unawares and photographed beautifully by the hugely talented, Dan Bowden on a visit to the city.
Friday 3 September 2021
HETEROMORPH AMMONITE: AINOCERAS
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. These little cuties were predators who hunted in Cretaceous seas.
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.
Not all ammonites have this whacky corkscrew design. Most are coiled and some are even shaped like massive paperclips. This one is so remarkable, so joyously perfect my internal thesaurus can’t keep up.
Thursday 2 September 2021
ABALONE: GWA'LIT'SA
Tuesday 31 August 2021
AIOLOCERAS BESAIRIEI: VIPS COLLECTION
Aioloceras besairiei (Collingnon, 1949) |
This is specimen #00783B in the collections of the Vancouver Palaeontological Society, (VIPS). The chambers have a wonderful calcite filling best viewed by carefully slicing these specimens in two.
There is a small imperfection near the centre that renders this ammonite its signature mark of perfection. This lovely is in my care as a study specimen.
Madagascar is an island country is about 400 kilometres off the coast of East Africa in the Indian Ocean and a wonderful place to explore off the beaten track. Exotic, beautiful and geologically interesting — it remains high on my bucket list to explore.
Madagascar has some of the most pleasing of all the fossil specimens I have ever seen. This beauty is no exception. The shell has a generally small umbilicus, arched to acute centre and falcoid ribs that spring in pairs from the umbilical tubercles then disappear on the outer whorls. Take that magical body plan with its pleasing symmetry and add an infilling with spectacular calcite — spectacular!
It is rightfully Aioloceras besairiei — and correctly labelled as such by the VIPS — but some specimens I have looked at earlier were marked as a Cleoniceras besairiei. This is impossible, of course, as Cleoniceras and Grycia are not present in Madagascar. This lovely, seen in cross-section, is now far from home and in my collection to enjoy for a time before returning to Courtenay on Vancouver Island.
Aioloceras besairiei are within beudanticeratinae. Cleoniceras and Grycia are the boreal genera. If you would like to see — or argue — the rationale on the name, consider reading Riccardi and Medina's riveting work from back in 2002, or Collingnon from 1949.
The beauty you see here measures in at a whopping 23 cm. It hails from the youngest or uppermost subdivision of the Lower Cretaceous. I had originally thought this locality was older, but dating reveals it to be from the Lower Albian, approximately 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma. This locality produces ammonites that are beyond measure in their singular beauty.
Aioloceras are found in the Cretaceous of Madagascar at geo coordinates 16.5° S, 45.9° E: paleo-coordinates 40.5° S, 29.3° E.; and in four localities in South Africa: at locality 36, near the Mzinene River at 28.0° S, 32.3° E: paleo-coordinates 48.6° S, 7.6° E.
We find them near the Mziene River, at a second locality north of Hluhluwe where the Mzinene Formation overlies the Aptian-Albian Makatini Formation at 28.0° S, 32.3° E: paleo-coordinates 48.6° S, 7.6° E; and at Haughton Z18, on the Pongola River in the Albian III, Tegoceras mosense beds at 27.3° S, 32.2° E: paleo-coordinates 48.0° S, 7.8° E.
If you happen to be trekking to Madagascar, know that it's big. It is 592,800 square kilometres (or 226,917 square miles), making it the fourth-largest island on the planet — bigger than Spain, Thailand, Sweden and Germany. So, enjoy your time and wear comfortable shoes.
If you are interested in learning more about this species, check out the Treatise on Invertebrate Paleontology, Part L (Ammonoidea). R.C. Moore (ed). Geological Soc of America and Univ. Kansas Press (1957), p L394. Or head over to look at the 2002 paper from Riccardi and Medina. 2002. Riccardi, A., C. & Medina, F., A. The Beudanticeratinae and Cleoniceratinae (Ammonitina) from the Lower Albian of Patagonia in Revue de Paléobiologie - 21(1) - Muséum d’Histoire Naturelle de la ville de Genève, p 313-314 (=Aioloceras besairiei (COLLIGNON, 1949). You have Bertrand Matrion to thank for the naming correction. Good to have friends in geeky places!
Collignon, M., 1933, Fossiles cenomaniens d’Antmahavelona (Province d’ Analalave, Madagascar), Ann. Geol. Serv. Min. Madagascar, III, 1934 Les Cephalopods du Trias inferieur de Madagascar, Ann. Paleont. XXII 3 and 4, XXII 1.
Besairie, H., 1971, Geologie de Madagascar, 1. Les terrains sedimentaires, Ann. Geol. Madagascar, 35, p. 463.
J. Boast A. and E. M. Nairn collaborated on a chapter in An Outline of the Geology of Madagascar, that is very readable and cites most of the available geologic research papers. It is an excellent place to begin a paleo exploration of the island.
If you happen to parle français, check out: Madagascar ammonites: http://www.ammonites.fr/Geo/Madagascar.htm
Sunday 29 August 2021
BLUE DRAGON SEA SLUG
By any name, they are a very pleasing addition to our planet. Glaucus atlanticus are a species of small, blue sea slug, a pelagic aeolid nudibranch — a shell-less gastropod mollusc in the family Glaucidae.
Nudibranchs likely date back as far as the Early Jurassic, some180 million years ago. This was around the time that the supercontinent of Pangea was breaking apart to form the modern continents and the Atlantic and Indian Oceans. The date is an estimate built upon the evolutionary lineages of their closest relatives, in part because the soft-bodied nature of nudibranchs means they do not fossilize well.
These sea slugs are pelagic — they float upside down by using the surface tension of the water to stay up near the surface where they drift along, carried by the winds and ocean currents. Glaucus atlanticus makes use of countershading: the blue side of their body faces upwards, blending in with the blue of the water. The silver/grey side of the sea slugs faces downwards, blending in with the sunlight reflecting on the ocean's surface when viewed facing upwards underwater, helping them avoid becoming a tasty snack.
Glaucus atlanticus feed on other pelagic creatures, including the Portuguese man o' war and other venomous siphonophores. This sea slug stores stinging nematocysts from the siphonophores within its own tissues as a defence against predators. Humans handling the slug may receive a very painful and potentially dangerous sting. Good on you little Dragon!
Saturday 28 August 2021
SERENE SIRENIA
They shared a cousin in the Steller's sea cow, Hydrodamalis gigas, but that piece of their lineage was hunted to extinction by our species in the 18th century.
Dugongs have tail flukes with pointed tips — similar to whales — and manatees have paddle-shaped tails, similar to a Canadian Beaver.
Both of these lovelies from the order Sirenia went from terrestrial to marine, taking to the water in search of more prosperous pastures, as it were.
We find dugongs today in waters near northern Australia and parts of the Indian and Pacific Oceans.
They inhabit rivers and shallow coastal waters, making the best use of their fusiform bodies that lack dorsal fins and hind limbs. I have been thinking about them in the context of some of the primitive armoured fish we find in the Chengjiang biota of China, specifically those primitive species that were also fusiform.
They favour locations where seagrass, their food of choice, grows plentiful and they eat it roots and all. While seagrass low in fibre, high in nitrogen, and easily digestible is preferred, dugongs will also dine on lower grade seagrass, algae, and invertebrates should the opportunity arise. They have been known to eat jellyfish, sea squirts, and shellfish over the course of their long lives.
Some of the oldest dugongs have been known to live 70+ years, which is another statistic I find surprising. They are large, passive, have poor eyesight, and look pretty tasty floating in the water; a defenceless floating buffet. Their population is in decline and yet they live on.
Friday 27 August 2021
ICE AGE MANATEES
Interestingly, we have recently found fossil evidence for manatees along the Texas coast dating back to the most recent ice age.
The discovery raises questions about whether manatees have been visiting for thousands of years, or if an ancient population of ice age manatees once called Texas home.
The findings were published in Palaeontologia Electronica by lead author Christopher Bell, a professor at the UT Jackson School of Geosciences with co-authors Sam Houston State University Natural History Collections curator William Godwin and SHSU alumna Kelsey Jenkins — now a graduate student at Yale University — and SHSU Professor Patrick Lewis.
The eight fossils described in the paper include manatee jawbones and rib fragments from the Pleistocene, the geological epoch of the last ice age. Most of the bones were collected from McFaddin Beach near Port Arthur and Caplen Beach near Galveston during the past 50 years by amateur fossil collectors who donated their finds to the SHSU collections.
The Jackson Museum of Earth History at UT holds two of the specimens. A lower jawbone fossil, which was donated to the SHSU collections by amateur collector Joe Liggio, jumpstarted the research.
Manatee jawbones have a distinct S-shaped curve that immediately caught Godwin's eye. But Godwin said he was met with scepticism when he sought other manatee fossils for comparison. He recalls reaching out to a local fossil enthusiast who told him point-blank, "there are no Pleistocene manatees in Texas."
But an examination of the fossils by Bell and Lewis proved otherwise. The bones belonged to the same species of manatee that visits the Texas coast today, Trichechus manatus. An upper jawbone donated by U.S. Rep. Brian Babin was found to belong to an extinct form of the manatee, Trichechus manatus bakerorum.
The age of the manatee fossils is based on their association with better-known ice age fossils and paleo-Indian artefacts that have been found on the same beaches.
It is assumed that the cooler ice age climate would have made Texas waters even less hospitable to manatees than they are today. But the fact that manatees were in Texas — whether as visitors or residents — raises questions about the ancient environment and ancient manatees. The Texas coast stretched much farther into the Gulf of Mexico and hosted wider river outlets during the ice age than it does today. Either the coastal climate was warmer than is generally thought, or ice age manatees were more resilient to cooler temperatures than manatees of today.
Subsurface imaging of the now flooded modern continental shelf reveals both a greater number of coastal embayments and the presence of significantly wider channels during ice age times.
If there was a population of ice age manatees in Texas, it is entirely plausible that they would have ridden out winters in these warmer river outlets similar to how they do today in Florida and Mexico.
Reference: Christopher Bell, William Godwin, Kelsey Jenkins, Patrick Lewis. First fossil manatees in Texas: Trichechus manatus bakerorum in the Pleistocene fauna from beach deposits along the Texas Coast of the Gulf of Mexico. Palaeontologia Electronica, 2020; DOI: 10.26879/1006
Wednesday 25 August 2021
SHORE CRAB: CARCINUS MAENAS / KU'MIS
European Green Shore Crab / Carcinus maenas |
They make a living off the seafloor, dining on worms, molluscs, small crustaceans and any number of bits and pieces that fall their way.
Shore Crabs are euryhaline, meaning they can tolerate a wide range of salinities (4 to 52 %), and survive in temperatures of zero to 30 °C (32 to 86 °F). This adaptability gives them a very wide range and competitive edge. This fellow is from the chilly waters of central Norway. The ability to eat pretty near anything and survive in extremely cold climates means he'll do quite well beneath the ice this winter.
Tuesday 24 August 2021
GULLS: TSIK'WI
A gull cries in protest at not getting his share of a meal |
Sunday 22 August 2021
CAVE BEAR: URSUS URALENSIS
Both the cave bear and the brown bear are thought to be descended from the Plio-Pleistocene Etruscan bear, Ursus etruscus, that lived about 5.3 Mya to 100,000 years ago.
The last common ancestor of cave bears and brown bears lived between 1.2–1.4 Mya. The immediate precursor of the cave bear was probably Ursus deningeri, the Deninger's bear — a species restricted to Pleistocene Europe about 1.8 Mya to 100,000 years ago.
The transition between Deninger's bear and the cave bear is given as the last interglacial, although the boundary between these forms is arbitrary, and intermediate or transitional taxa have been proposed, Ursus spelaeus deningeroides, while other authorities consider both taxa to be chronological variants of the same species.
Cave bears found in different regions vary in age, thus facilitating investigations into evolutionary trends. The three anterior premolars were gradually reduced, then disappeared, possibly in response to a largely vegetarian diet.
In a fourth of the skulls found in the Conturines, the third premolar is still present, while more derived specimens elsewhere lack it. The last remaining premolar became conjugated with the true molars, enlarging the crown and granting it more cusps and cutting borders. This phenomenon, called molarization, improved the mastication capacities of the molars, facilitating the processing of tough vegetation. This allowed the cave bear to gain more energy for hibernation while eating less than its ancestors.
A lone Grizzly Bear / Na̱ndzi |
The procedure used genomic DNA extracted from one of the animal's teeth. Sequencing the DNA directly (rather than first replicating it with the polymerase chain reaction), the scientists recovered 21 cave bear genes from remains that did not yield significant amounts of DNA with traditional techniques.
This study confirmed and built on results from a previous study using mitochondrial DNA extracted from cave bear remains ranging from 20,000 to 130,000 years old.
Both show that the cave bear was more closely related to the brown bear and polar bear than it was to the American black bear, but had split from the brown bear lineage before the distinct eastern and western brown bear lineages diversified and before the split of brown bears and polar bears. The divergence date estimate of cave bears and brown bears is about 1.2–1.4 Mya. However, a recent study showed that both species had some hybridization between them.
We are blessed to have them living amongst us today on the rugged west coast of British Columbia. In the Kwak'wala language of the Kwakiutl First Nations of the Pacific Northwest, this big fellow is na̱ndzi — a lovely, large peaceful bear.
Saturday 21 August 2021
MUSKOX: CAPRINAE
As a member of the subfamily Caprinae of the family Bovidae, the muskox is more closely related to sheep and goats than to oxen. It has been placed in its own genus, Ovibos — Latin for sheep-ox. It is one of the two largest extant members of Caprinae, along with the similarly sized takin.
While the takin and muskox were once considered possibly closely related, the takin lacks common ovibovine features, such as the muskox's specialized horn morphology, and genetic analysis shows that their lineages actually separated early in caprine evolution.
Instead, the muskox's closest living relatives appear to be the gorals of the genus Naemorhedus, nowadays common in many countries of central and east Asia. The vague similarity between takin and muskox must therefore be considered an example of convergent evolution.
The modern muskox is the last member of a line of ovibovines that first evolved in temperate regions of Asia and adapted to a cold tundra environment late in its evolutionary history. They lived alongside our lovely Mammoths and would have competed for the same plant resources as those much larger beasts.
Muskox ancestors with sheep-like high-positioned horns — horn cores being mostly over the plane of the frontal bones, rather than below them as in modern muskoxen — first left the temperate forests for the developing grasslands of Central Asia during the Pliocene, expanding into Siberia and the rest of northern Eurasia.
Later migration waves of Asian ungulates, including the high-horned muskox, reached Europe and North America during the first half of the Pleistocene. The first well-known muskox, the "shrub-ox" Euceratherium, crossed to North America over an early version of the Bering Land Bridge two million years ago and prospered in the American southwest and Mexico. Euceratherium was larger yet more lightly built than modern muskoxen, resembling a giant sheep with massive horns, and preferred hilly grasslands.
A genus with intermediate horns, Soergelia, inhabited Eurasia in the early Pleistocene, from Spain to Siberia, and crossed to North America during the Irvingtonian (1.8 million years to 240,000 years ago), soon after Euceratherium. Unlike Euceratherium, which survived in America until the Pleistocene-Holocene extinction event, Soergelia was a lowland dweller that disappeared fairly early, displaced by more advanced ungulates, such as the "giant muskox" Praeovibos (literally "before Ovibos").
The low-horned Praeovibos was present in Europe and the Mediterranean 1.5 million years ago, colonized Alaska and the Yukon one million years ago and disappeared half a million years ago. Praeovibos was a highly adaptable animal that appears associated with cold tundra (reindeer) and temperate woodland (red deer) faunas alike.
During the Mindel glaciation 500,000 years ago, Praeovibos was present in the Kolyma river area in eastern Siberia in association with many Ice Age megafauna that would later coexist with Ovibos, in the Kolyma itself and elsewhere, including wild horses, reindeer, woolly mammoth and stag-moose.
It is debated, however, if Praeovibos was directly ancestral to Ovibos, or both genera descended from a common ancestor since the two occurred together during the middle Pleistocene. Defenders of ancestry from Praeovibos have proposed that Praeovibos evolved into Ovibos in one region during a period of isolation and expanded later, replacing the remaining populations of Praeovibos.
Two more Praeovibos-like genera were named in America in the 19th century, Bootherium and Symbos, which are now identified as the male and female forms of a single, sexually dimorphic species, the "woodland muskox", Bootherium bombifrons. Bootherium inhabited open woodland areas of North America during the Late Pleistocene, from Alaska to Texas and maybe even Mexico, but was most common in the Southern United States, while Ovibos replaced it in the tundra-steppe to the north, immediately south of the Laurentian ice sheet.
Modern Ovibos appeared in Germany almost one million years ago and were common in the region through the Pleistocene. Muskoxen had also reached the British Isles. Both Germany and Britain were just south of the Scandinavian ice sheet and covered in the tundra during cold periods, but Pleistocene muskoxen are also rarely recorded in more benign and wooded areas to the south like France and Green Spain, where they coexisted with temperate ungulates like red deer and aurochs. Likewise, the muskox is known to have survived in Britain during warm interglacial periods.
Today's muskoxen are descended from others believed to have migrated from Siberia to North America between 200,000 and 90,000 years ago, having previously occupied Alaska (at the time united to Siberia and isolated periodically from the rest of North America by the union of the Laurentide and Cordilleran Ice Sheets during colder periods) between 250,000 and 150,000 years ago.
After migrating south during one of the warmer periods of the Illinoian glaciation, non-Alaskan American muskoxen would be isolated from the rest in the colder periods. The muskox was already present in its current stronghold of Banks Island 34,000 years ago, but the existence of other ice-free areas in the Canadian Arctic Archipelago at the time is disputed.
Along with the bison and the pronghorn, the muskox was one of a few species of Pleistocene megafauna in North America to survive the Pleistocene/Holocene extinction event and live to the present day. The muskox is thought to have been able to survive the last glacial period by finding ice-free areas (refugia) away from prehistoric peoples.
Fossil DNA evidence suggests that muskoxen were not only more geographically widespread during the Pleistocene, but also more genetically diverse. During that time, other populations of muskoxen lived across the Arctic, from the Ural Mountains to Greenland. By contrast, the current genetic makeup of the species is more homogenous. Climate fluctuation may have affected this shift in genetic diversity: research indicates colder periods in Earth's history are correlated with more diversity and warmer periods with more homogeneity.
Friday 20 August 2021
ORIGINS OF THE WOOLLY MAMMOTHS
Over time, their body size shrank and their teeth and tusks evolved to take advantage of the tough vegetation available to those few animals who could chew their way through ice and snow and work these tundra grasses into a digestible form.
The enamel plates of their cheek teeth multiplied while the enamel itself became thinner. Tusks slowly took on more of a curved to act as ploughs for the snow.Those smaller than their predecessors, they were still formidable. Their size offered protection against predators once full grown. Sadly for the juveniles, they offered tasty prey to big cats like Homotherium who roamed these ancient grasslands alongside them.
The Mammoths of the Steppe spread to the northern areas of Eurasia, down through Europe, into the British Isles to Spain and crossed over to populate North America via the Bering Isthmus. It was the lowered sea levels during the last Ice Age that exposed dry land between Asia and the Americas. Here in this flat, grassy treeless plain known as the Bering Land Bridge or Isthmus, animals, including humans, could migrate from Europe west into North America.
The woolly mammoth coexisted with our ancestors who made good use of their bones and tusks for tools, housing, art and food. The last of their lineage died out relatively recently on Wrangel Island until 4,000 years ago — a time when we were making our first harps and flutes in Egypt, dams, canals and stone sculptures in Sumer, using numbers for the first time and using tin to make tools.