SUNRISE FORMATION, NEVADA

At the entrance to the Pliensbachian-Toarcian localities at Joker Peak and Mina Peak Members of the Sunrise Formation, Nevada, USA.

The ammonites of this section were first studied by Dr. Paul Smith, past Chair of Earth and Ocean Sciences, University of British Columbia and more recently by Andrew Caruthers et al.

Caruthers and his team also took a goodly look at the Early Jurassic coral fauna. Caruthers is an interesting cat. He uses a combination of invertebrate paleontology and isotope geochemistry to ponder the effects of paleoclimate change and mass extinction. He's turned his eye in recent years to the Paleozoic of the Michigan Basin AND he's based in Kalamazoo, MI. Yep, Kalamazoo.

Others have taken up the mantle of discovery from these sites. Pengfei Hou did his 2014 Masters thesis comparing the Sinemurian (Early Jurassic) stratigraphic sections of Last Creek, British Columbia and Five Card Draw, Nevada including a detailed taxonomic study from the Involutum Zone to the lower part of the Harbledownense Zone of the Sinemurian.

DUBIOUS DAONELLA DUBIA

Triassic ammonoids, West Humboldt Mountains, Nevada, USA. This was 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.

Paleontologist J.P. Smith joined that expedition and published on the marine fauna in the early 1900s.

They formed the basis for his monograph on North American Middle Triassic marine invertebrate fauna published in 1914. N. J. Siberling from the US Geological Survey published on these outcrops in 1962. His work included nearly a dozen successive ammonite faunas, many of which were variants on previously described species.

Evidently, his collections consisted mainly of weathered material and were made without stratigraphic control because he believed that most, if not all, of these species, were coexistent. The fossiliferous beds found here, as well as localities in north-western Nevada, were designated the 'Daonella dubia' zone. Dubious would be closer to the truth. We've since mapped them out from stratigraphic sections to place them in the correct order of their occurrence.

SMILODON FATALIS

During the last ice age, huge cats bigger than an African lion prowled Alberta, including the fearsome beast commonly known as the sabre-toothed tiger.

The proper name for the extinct predator with foot-long, serrated knife-like canines is Smilodon fatalis.

Up until the discovery of the fossil from Medicine Hat, Alberta, the species had never been found further north than Idaho. Or so it was thought...

A few years ago, a few small fossils caught the eye of researcher Ashley Reynolds as she was rummaging through the drawers at the Royal Ontario Museum in Toronto. The drawer was part of a treasure trove of 1,200 specimens collected in the 1960s by University of Toronto palaeontologist C.S. Churcher and his team. The specimens were collected over many field seasons along the bluffs of the South Saskatchewan River near Medicine Hat.

Churcher was a palaeontologist with a keen eye and a delightful man. I had the very great pleasure of listening to many of his talks out at UBC and at a few VanPS meetings in the mid-2000s. "Rufus" was a thoroughly charming storyteller and shared many of his adventures from the field. He moved out to the West Coast for his retirement but his keen love of the science kept him giving talks to enthralled listeners keen to hear about his survey of the Dakhleh Oasis in the Western Desert of Egypt, geomorphology, stratigraphy, recent biology, Pleistocene and Holocene lithic cultures, insights learned from Neolithic Islamic pottery to Roman settlements.

The specimens he had collected had been roughly sorted but never examined in detail. Reynolds, who was researching the growth patterns and life histories of extinct cats by looking at their bones, decided to look more carefully at the fossils Churcher had found, keen to add them to her research. And what a find she made!

One of the fossils labelled Smilodon was too small a piece to be identified. But another, a bone from the ancient cat's right front paw, was identical to other Smilodon bones and was positively identified as Canada's first Smilodon. CBC did a nice write up on her discoveries. 

References:
https://www.cbc.ca/n…/technology/sabre-toothed-cat-1.5305505

LATE HETTANGIAN TO EARLY SINEMURIAN FAUNA

Hiking the hills of Nevada looking for David Taylor's faunal succession based on ammonoids established for the Late Hettangian to Early Sinemurian interval in the Western Cordillera.

It was a tremendous experience to walk through time and compare the fossil assemblages here with our own in the Canadian Rockies.

Here the faunal sequence consists of one zone and four informal biochronologic units or assemblages and was outlined by Taylor as follows: Paracaloceras morganense assemblage, Badouxia oregonensis assemblage, Canadensis Zone, Metophioceras trigonatum assemblage and Coroniceras involutum. They matched up to specimens we collected over three field seasons to similar faunal outcrops of Late Hettangian to Early Sinemurian of the Last Creek and Tyaughton area of the Canadian Rockies.

The succession also correlates with the interval delineated by the Northwest European Angulata Zone through the Lyra Subzone. Two new genera (Guexiceras and Tipperoceras) are described along with 23 new species. The phylogenetic relationships of the earliest Jurassic ammonite superfamilies indicate that it is useful to include under the Psiloceratida, the Psilocerataceae and their derivatives including the Lytocerataceae. The Arietitaceae were derived from Hettangian lytocerataceans.