In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, hummingbirds are known as k̕wa̱'ak̕wa̱mt̕a.
Tuesday 27 December 2016
HUMMINGBIRD: K'WA'AK'WAMT'A
Monday 26 December 2016
Thursday 22 December 2016
AMMONITE TIME KEEPERS
Argonauticeras besairei, José Juárez Ruiz |
Ammonites were predatory, squidlike creatures that lived inside coil-shaped shells.
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 am 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.
The Ammonoidea can be divided into six orders:
- Agoniatitida, Lower Devonian - Middle Devonian
- Clymeniida, Upper Devonian
- Goniatitida, Middle Devonian - Upper Permian
- Prolecanitida, Upper Devonian - Upper Triassic
- Ceratitida, Upper Permian - Upper Triassic
- Ammonitida, Lower Jurassic - Upper Cretaceous
Ammonites have intricate and complex patterns on their shells called sutures. The suture patterns differ across species and tell us what time period the ammonite is from. If they are geometric with numerous undivided lobes and saddles and eight lobes around the conch, we refer to their pattern as goniatitic, a characteristic of Paleozoic ammonites.
If they are ceratitic with lobes that have subdivided tips; giving them a saw-toothed appearance and rounded undivided saddles, they are likely Triassic. For some lovely Triassic ammonites, take a look at the specimens that come out of Hallstatt, Austria and from the outcrops in the Humboldt Mountains of Nevada.
Hoplites bennettiana (Sowby, 1826) Christophe Marot |
One of my favourite Cretaceous ammonites is the ammonite, Hoplites bennettiana (Sowby, 1826). This beauty is from Albian deposits near Carrière de Courcelles, Villemoyenne, near la région de Troyes (Aube) Champagne in northeastern France.
At the time that this fellow was swimming in our oceans, ankylosaurs were strolling about Mongolia and stomping through the foliage in Utah, Kansas and Texas. Bony fish were swimming over what would become the strata making up Canada, the Czech Republic and Australia. Cartilaginous fish were prowling the western interior seaway of North America and a strange extinct herbivorous mammal, Eobaatar, was snuffling through Mongolia, Spain and England.
In some classifications, these are left as suborders, included in only three orders: Goniatitida, Ceratitida, and Ammonitida. Once you get to know them, ammonites in their various shapes and suturing patterns make it much easier to date an ammonite and the rock formation where it is found.
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 of rock to match up to specific geologic time periods, rather like the way we use tree rings to date trees. A handy way to compare fossils and date strata across the globe.
References: Inoue, S., Kondo, S. Suture pattern formation in ammonites and the unknown rear mantle structure. Sci Rep 6, 33689 (2016). https://doi.org/10.1038/srep33689
https://www.nature.com/articles/srep33689?fbclid=IwAR1BhBrDqhv8LDjqF60EXdfLR7wPE4zDivwGORTUEgCd2GghD5W7KOfg6Co#citeas
Photos: Argonauticeras besairei from the awesome José Juárez Ruiz.
Photo: Hoplites bennettiana from near Troyes, France. Collection de Christophe Marot
Wednesday 21 December 2016
Tuesday 20 December 2016
DRAGONFLIES: ODONATA
Time has turned the tables. Small lizards and birds who today choose dragonflies as a tasty snack used to be their preferred prey.
Sunday 18 December 2016
LOWER CRETACEOUS ACANTHOHOPLITES
Geologically, the Caucasus Mountains belong to a system that extends from southeastern Europe into Asia and is considered a border between them. The Greater Caucasus Mountains are mainly composed of Cretaceous and Jurassic rocks with the Paleozoic and Precambrian rocks in the higher regions.
Some volcanic formations are found throughout the range. On the other hand, the Lesser Caucasus Mountains are formed predominantly of the Paleogene rocks with a much smaller portion of the Jurassic and Cretaceous rocks.
The evolution of the Caucasus began from the Late Triassic to the Late Jurassic during the Cimmerian orogeny at the active margin of the Tethys Ocean while the uplift of the Greater Caucasus is dated to the Miocene during the Alpine orogeny.
The Caucasus Mountains formed largely as the result of a tectonic plate collision between the Arabian plate moving northwards with respect to the Eurasian plate. As the Tethys Sea was closed and the Arabian Plate collided with the Iranian Plate and was pushed against it and with the clockwise movement of the Eurasian Plate towards the Iranian Plate and their final collision, the Iranian Plate was pressed against the Eurasian Plate.
As this happened, the entire rocks that had been deposited in this basin from the Jurassic to the Miocene were folded to form the Greater Caucasus Mountains. This collision also caused the uplift and the Cenozoic volcanic activity in the Lesser Caucasus Mountains.
The preservation of this Russian specimen is outstanding. Acanthohoplites bigoureti are also found in Madagascar, Mozambique, in the Rhone-Alps of France and the Western High Atlas Mountains and near Marrakech in Morocco. This specimen measures 55mm and is in the collection of the deeply awesome Emil Black.
Thursday 15 December 2016
Tuesday 13 December 2016
HALL OF GIANTS NEW MEXICO
Sunday 11 December 2016
Saturday 10 December 2016
Friday 9 December 2016
CARNOTAURUS SASTREI
This fellow (or at least his skull) is on display at the Natural History Museum in Madrid, Spain. For now, he is the only known genus of this species of bipedal predator.
The skull is quite unusual. Initially, it has a very marine reptile feel (but make no mistake this guy is clearly a terrestrial theropod). Once you look closer you see his bull-like horns (from whence he gets his name) that imply battle between rivals for the best meal, sexual partner and to be the one who leads the herd.
I'll be interested to see his cousins once more specimens of the genus are unearthed.
Thursday 8 December 2016
Wednesday 7 December 2016
OLD HABITS IN CORDOBA SPAIN
Nuns stepping out from the palace, Cordoba, Spain |
Tuesday 6 December 2016
Saturday 3 December 2016
SHARKS: ELASMOBRANCH FISH
Modern sharks are classified within the clade Selachimorpha and are the sister group to the rays.
While we often fear them — yes, they can eat you — they should fear us as we dine on them with shocking regularity. In lieu of Shark Fin Soup, a better choice would be investing money and time into their conservation.
Thursday 1 December 2016
Sunday 27 November 2016
40 DEGREES OF LATITUDE: THE ROCKIES
But the niggling thought is still there. Is there one a single element I could name that epitomizes this vast, diverse landscape? Sea to Sky, lakes to mountains, I've kayaked, hiked, sailed and lovingly explored a great deal of it. Through 40 degrees of latitude, from Yukon to Mexico, the Rocky Mountains are North America's geographic backbone.
This is the Great Continental Divide, where the interminable flatness of the interior collides with the Western Cordillera, a major mountain system of the world. From the highest ridges of the Rockies, the rivers flow to opposite corners of the land, north to the Beaufort Sea, south to the Gulf of Mexico, east to Hudson Bay and west to the Pacific.
Friday 25 November 2016
KWAS'KWAS: OUR BEAUTIFUL BLUE JAYS
Tuesday 15 November 2016
Monday 14 November 2016
AMMONITES OF THE ARNIOCERAS BEDS
Several ammonites species can be found here including Arnioceras semicostatum & Arnioceras miserable. The two gastropods you see in the central block have yet to be identified to species. Here's hoping a nice grad student takes an interest. The rare but lovely gastros from this area would make an excellent thesis. Perhaps comparing their distribution to their counterparts in Europe.
Saturday 12 November 2016
CRETACEOUS BONE BEDS
Einiosaurus procurvicornis was a horned dinosaur that roamed North America 74 million years ago. We find their bones in mass bone beds in Cretaceous outcrops of Montana and the Blackfeet Nation. The fossils have been recovered from rich bonebeds, largely consisting of only Einiosaurus fossils. Bonebeds with only one species are called monospecific bonebeds. But why do they occur?
The most commonly suggested reason is that a herd of animals was suddenly killed by a natural disaster, like a volcanic eruption or flood.
Their bodies were buried and remained in proximity to each other as they preserved, and today excavations uncover the remains of the unfortunate herd. Multiple other monospecific bonebeds have been found for other species of horned dinosaurs, such as Achelousaurus, causing researchers to suggest some groups of horned dinosaurs did exhibit herding behaviour— and that sometimes they met sudden unfortunate ends. But is sudden mass death from a natural disaster the only reason for monospecific bonebeds?
Researchers say no. While the monospecific nature is still largely argued to represent herding in many cases, natural disaster is not always the cause of death. Sometimes large numbers of animals die from disease or starvation. Their carcasses could later be pushed together and buried by an event like a mudflow unrelated to their deaths. Their bones could also sit on the surface for years before an event that buries them.
To understand the cause of a bonebed, researchers look at the bones themselves and the sediment that surrounds them. Bonebeds can tell us a lot about how these animals were living— but there is a lot to be learned from trying to figure out how they died, too.
Currie, P. J., & Padian, K. (Eds.). (1997). Encyclopedia of dinosaurs. Elsevier. • Rogers, R. R. (1989). Taphonomy of three monospecific dinosaur bone beds in the Late Cretaceous Two Medicine Formation northwestern Montana: Evidence for dinosaur mass mortality related to episodic drought. Graduate Student Theses, Dissertations, & Professional Papers. 5871. • Sampson, S. D. (1995).
Two new horned dinosaurs from the Upper Cretaceous Two Medicine Formation of Montana; with a phylogenetic analysis of the Centrosaurinae (Ornithischia: Ceratopsidae). Journal of Vertebrate Paleontology, 15(4), 743-760. • Schmitt, J. G., Jackson, F. D., & Hanna, R. R. (2014). Debris flow origin of an unusual late Cretaceous hadrosaur bonebed in the Two Medicine Formation of western Montana. Hadrosaurs. Indiana Press, Bloomington, 486-501.
Friday 11 November 2016
Wednesday 26 October 2016
MIGHTY EAGLE: KWIKW (KW-EE-KW)
Bald Eagle / Kwikw / Haliaeetus leucocephalus |
Thursday 13 October 2016
Tuesday 11 October 2016
Thursday 29 September 2016
Monday 26 September 2016
SAUROPTERYGIANS
Their oldest relatives were small, semi-aquatic reptiles with four limbs that were adapted for paddling around in shallow water. By the end of the Triassic, they had grown to much larger animals fully adapted to a life at sea and were incapable of coming to shore.
Throughout the Jurassic and the Cretaceous developed a diverse range of body plans adapted for a life in the water. They went extinct at the end of the Cretaceous along with the dinosaurs.
The best known of the sauropterygians are the long neck Plesiosaurs but this taxon includes a whole host of other interesting Mesozoic marine reptiles. then flourished during the Mesozoic.
Sauropterygians are united by a radical adaptation of their pectoral girdle, designed to support powerful flipper strokes. While Tyrannosaurs ruled the land, and flying reptiles ruled the skies, the mighty Mosasaurs dominated the seas. They were late to the aquatic party, being the last clade to evolve. Photo: By Ryan Somma - PlesiosaurusUploaded by FunkMonk, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=6735975
Friday 9 September 2016
Wednesday 7 September 2016
Sunday 4 September 2016
BRITISH COLUMBIA'S GREAT BEARS
Both bear families descend from a common ancestor, Ursavus, a bear-dog the size of a raccoon who lived more than 20 million years ago. Seems an implausible lineage given the size of their very large descendents.
An average Grizzly weighs in around 800 lbs (363 kg), but a recent find in Alaska tops the charts at 1600 lbs (726 kg). This mighty beast stood 12' 6' high at the shoulder, 14' to the top of his head. It is one of the largest grizzly bears ever recorded. This past month this king of the forest was seen once again in the Washington Cascades -- the first sighting in 50 years.