Icacinaceae in the early middle Paleocene Raton Formation, Colorado

2018 ◽  
Vol 55 (2) ◽  
pp. 75-86 ◽  
Author(s):  
Keith Berry

Icacinicaryites corruga is reported from the upper coal zone of the Raton Formation in south-central Colorado. Prior to this report, this endocarp imprint was known from only a single locality near Pagosa Springs in southwestern Colorado (Animas Formation). This demonstrates that Icacinaceae, which characterized the late Paleocene – early Eocene tropical rainforests of western North America, already were present in Colorado’s early middle Paleocene tropical rainforest. This determination agrees with the results of a reevaluation of the stratigraphic distribution of previous records of Icacinaceae from the Paleocene of western North America.

2000 ◽  
Vol 37 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Lance Grande ◽  
Li Guo-Qing ◽  
Mark VH Wilson

A well-prepared anterior half of an amiid skull from the Late Paleocene Paskapoo Formation of south-central Alberta is described. The specimen is either very closely related to, or conspecific with, Amia pattersoni Grande and Bemis, 1998, from the Early Eocene Green River Formation of Wyoming. We leave the specimen as Amia cf. pattersoni until additional material is found to further clarify its relationships. Amia cf. pattersoni is the oldest known specimen clearly identifiable as belonging to the genus Amia (sensu Grande and Bemis, 1998), and the Paskapoo species extends the known geographic range of Amia both northward and westward. The fish assemblage of the Paskapoo Formation represents the most diverse freshwater Paleocene fish fauna known from North America. Based on comparisons of sample size and relative taxonomic diversity to the better known Green River Formation localities of Wyoming, we predict that further collecting will substantially increase the known diversity of the Paskapoo fauna. The Paskapoo Formation, therefore, has great potential to continue adding to the meager knowledge of pre-Eocene freshwater teleost diversity in North America.


2018 ◽  
Vol 150 (2) ◽  
pp. 205-257 ◽  
Author(s):  
S. B. Archibald ◽  
Alexandr P. Rasnitsyn ◽  
Denis J. Brothers ◽  
Rolf W. Mathewes

AbstractMost major modern families of Hymenoptera were established in the Mesozoic, but the diversifications within ecologically key trophic guilds and lineages that significantly influence the character of modern terrestrial ecosystems – bees (Apiformes), ants (Formicidae), social Vespidae, parasitoids (Ichneumonidae), and phytophagous Tenthredinoidea – were previously known to occur mostly in the middle to late Eocene. We find these changes earlier, seen here in the early Eocene Okanagan Highlands fossil deposits of western North America. Some of these may have occurred even earlier, but have been obscured by taphonomic processes. We provide an overview of the Okanagan Highlands Hymenoptera to family level and in some cases below that, with a minimum of 25 named families and at least 30 when those tentatively assigned or distinct at family level, but not named are included. Some are poorly known as fossils (Trigonalidae, Siricidae, Peradeniidae, Monomachidae), and some represent the oldest confirmed occurrences (Trigonalidae, Pompilidae, Sphecidaesensu stricto, Peradeniidae, Monomachidae, and possibly Halictidae). Some taxa previously thought to be relictual or extinct by the end of the Cretaceous (Angarosphecidae, Archaeoscoliinae, some Diapriidae) are present and sometimes abundant in the early Eocene. Living relatives of some taxa are now present in different climate regimes or on different continents.


Zootaxa ◽  
2021 ◽  
Vol 4980 (1) ◽  
pp. 142-156
Author(s):  
VLADIMIR N. MAKARKIN ◽  
S. BRUCE ARCHIBALD ◽  
ROLF W. MATHEWES

The osmylid subfamily Protosmylinae is revised based on our emended diagnosis: Petrushevskia Martynova, 1958 and Mesosmylidus Jepson et al., 2012 are excluded (both considered Osmylidae incertae sedis), and Sogjuta Martynova, 1958 is transferred to it from the Mesosmylininae. The late Eocene genus Protosmylus Krüger, 1913 is considered a junior synonym of Osmylidia Cockerell, 1908 based on a distinct apomorphy (deeply forked MA in the hind wing), syn. nov. Three new species of Osmylidia from the early Eocene of North America are described: O. donnae sp. nov. from Quilchena, O. glastrai sp. nov. from Republic, Washington, USA, and an unnamed species of Osmylidia is reported from Driftwood Canyon Provincial Park, British Columbia (all localities of the Okanagan Highlands series), and O. taliae sp. nov. from the Green River Formation of Colorado, USA. 


2005 ◽  
Vol 142 (4) ◽  
pp. 377-398 ◽  
Author(s):  
J. M. ADRAIN ◽  
S. R. WESTROP

The Notch Peak Formation (Late Cambrian, Sunwaptan) of western Utah yields diverse silicified trilobite faunas that provide new information on the anatomy of many taxa. The family Ptychaspididae Raymond, 1924, is represented by species of Keithiella Rasetti, 1944; Idiomesus Raymond, 1924; Euptychaspis Ulrich in Bridge, 1931; and Macronoda Lochman, 1964. At least four species are new, of which E. lawsonensis and M. notchpeakensis are named formally. Much previous work on Late Cambrian trilobites has emphasized biostratigraphic utility and the recognition of geographically widespread species. Data from new silicified collections indicate that this approach is difficult to justify because many putative ‘index species’ actually represent a plexus of closely related species whose biostratigraphic significance has yet to be determined. One such plexus is represented by E. kirki Kobayashi, 1935, whose previously reported occurrences in Texas, Oklahoma, Utah, Nevada and northern Canada record at least four distinct species. Similarly, Macronoda can now be shown to consist of at least five late Sunwaptan species in south-central and western North America.


2019 ◽  
Vol 56 (8) ◽  
pp. 803-813
Author(s):  
Gerald Mayr ◽  
S. Bruce Archibald ◽  
Gary W. Kaiser ◽  
Rolf W. Mathewes

We survey the known avian fossils from Ypresian (early Eocene) fossil sites of the North American Okanagan Highlands, mainly in British Columbia (Canada). All specimens represent taxa that were previously unknown from the Eocene of far-western North America. Wings from the McAbee site are tentatively referred to the Gaviiformes and would constitute the earliest fossil record of this group of birds. A postcranial skeleton from Driftwood Canyon is tentatively assigned to the Songziidae, a taxon originally established for fossils from the Ypresian of China. Two skeletons from Driftwood Canyon and the McAbee site are tentatively referred to Coliiformes and Zygodactylidae, respectively, whereas three further fossils from McAbee, Blakeburn, and Republic (Washington, USA) are too poorly preserved for even a tentative assignment. The specimens from the Okanagan Highlands inhabited relatively high paleoaltitudes with microthermal climates (except Quilchena: lower mesothermal) and mild winters, whereas most other Ypresian fossil birds are from much warmer lowland paleoenvironments with upper mesothermal to megathermal climates. The putative occurrence of a gaviiform bird is particularly noteworthy because diving birds are unknown from other lacustrine Ypresian fossil sites of the Northern Hemisphere. The bones of the putative zygodactylid show a sulphurous colouration, and we hypothesize that this highly unusual preservation may be due to the metabolic activity of sulphide-oxidizing bacteria.


2008 ◽  
Vol 95 (7) ◽  
pp. 824-832 ◽  
Author(s):  
Kathleen B. Pigg ◽  
Steven R. Manchester ◽  
Melanie L. DeVore

Geology ◽  
1991 ◽  
Vol 19 (12) ◽  
pp. 1189 ◽  
Author(s):  
Scott L. Wing ◽  
Thomas M. Bown ◽  
John D. Obradovich

Geosphere ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 1262-1290 ◽  
Author(s):  
Roderick W. Campbell ◽  
Luke P. Beranek ◽  
Stephen J. Piercey ◽  
Richard Friedman

AbstractPost-breakup magmatic rocks are recognized features of modern and ancient passive margin successions around the globe, but their timing and significance to non-plume-related rift evolution is generally uncertain. Along the Cordilleran margin of western North America, several competing rift models have been proposed to explain the origins of post-breakup igneous rocks that crop out from Yukon to Nevada. New zircon U-Pb age and whole-rock geochemical studies were conducted on the lower Paleozoic Kechika group, south-central Yukon, to test these rift models and constrain the timing, mantle source, and tectonic setting of post-breakup magmatism in the Canadian Cordillera. The Kechika group contains vent-proximal facies and sediment-sill complexes within the Cassiar platform, a linear paleogeographic high that developed outboard of continental shelf and trough basins. Chemical abrasion (CA-TIMS) U-Pb dates indicate that Kechika group mafic rocks were generated during the late Cambrian (488–483 Ma) and Early Ordovician (473 Ma). Whole-rock trace-element and Nd- and Hf-isotope results are consistent with the low-degree partial melting of an enriched lithospheric mantle source during margin-scale extension. Equivalent continental shelf and trough rocks along western North America are spatially associated with transfer-transform zones and faults that were episodically reactivated during Cordilleran rift evolution. Post-breakup rocks emplaced along the magma-poor North Atlantic margins, including those near the Orphan Knoll and Galicia Bank continental ribbons, are proposed modern analogues for the Kechika group. This scenario calls for the release of in-plane tensile stresses and off-axis, post-breakup magmatism along the nascent plate boundary prior to the onset of seafloor spreading.


2020 ◽  
Vol 94 (3) ◽  
pp. 557-567
Author(s):  
Walter G. Joyce ◽  
Julien Claude

AbstractCardichelyon rogerwoodi is an enigmatic fossil turtle from the late Paleocene to early Eocene of North America. Previous analyses suggested affiliation with Testudinoidea, in particular the big-headed turtle Platysternon megacephalum, based on the presence of multiple musk-duct foramina and a large head. We here highlight previously undocumented characteristics for this turtle, notably the presence of short costiform processes, a rib-like axillary process, and a posterior plastral hinge. Phylogenetic analysis places Cardichelyon rogerwoodi within Testudinoidea, but the exclusion of testudinoids suggest an affiliation with Dermatemydidae. Using consilience with external data we favor placement within Kinosternoidea. Cardichelyon rogerwoodi is therefore an aberrant, hinged kinosternoid that developed in situ in North America during the Paleocene long before the arrival of testudinoids on this continent in the early Eocene.


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