scholarly journals The second North American fossil horntail wood-wasp (Hymenoptera: Siricidae), from the early Eocene Green River Formation

Zootaxa ◽  
2021 ◽  
Vol 4999 (4) ◽  
pp. 325-334
Author(s):  
S. BRUCE ARCHIBALD ◽  
ARVID AASE ◽  
ANDRÉ NEL
Keyword(s):  
Climate Change ◽  
North America ◽  
Northern Hemisphere ◽  
North American ◽  
Green River Formation ◽  
Early Eocene ◽  
Green River ◽  
Tropical Lowlands

Eoteredon lacoi gen. et sp. nov., is described from the early Eocene Green River Formation in Wyoming, the second fossil siricid genus and species described from North America. We propose Eoteredon as sister to the genus Teredon, whose sole species is one of the rarest of extant Siricidae. The majority of siricids today inhabit temperate Northern Hemisphere forests; Teredon cubensis, however, is one of its few species that live in megathermal tropical lowlands. The Eocene forest that Eoteredon inhabited had a mesothermal to megathermal climate. We place Eoteredon in the context of broad Cenozoic climate change.

Amia cf. pattersoni from the Paleocene Paskapoo Formation of Alberta

2000 ◽  
Vol 37 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Lance Grande ◽  
Li Guo-Qing ◽  
Mark VH Wilson
Keyword(s):  
North America ◽  
Fish Fauna ◽  
Taxonomic Diversity ◽  
Geographic Range ◽  
Green River Formation ◽  
Early Eocene ◽  
Freshwater Teleost ◽  
Additional Material ◽  
Green River ◽  
South Central

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.

Early Eocene snakeflies (Raphidioptera) of western North America from the Okanagan Highlands and Green River Formation

Zootaxa ◽  
2021 ◽  
Vol 4951 (1) ◽  
pp. 41-79
Author(s):  
S. BRUCE ARCHIBALD ◽  
VLADIMIR N. MAKARKIN
Keyword(s):  
United States ◽  
British Columbia ◽  
North America ◽  
United States Of America ◽  
Green River Formation ◽  
Early Eocene ◽  
Western North America ◽  
Green River ◽  
The Family ◽  
Okanagan Highlands

Four new species of Raphidiidae are described from the early Eocene of western North America: Megaraphidia antiquissima sp. nov. from McAbee, M. ootsa sp. nov. from Driftwood Canyon, M. hopkinsi sp. nov. from the Allenby Formation (all from British Columbia, Canada), M. klondika sp. nov. from Republic (Washington, United States of America). Archiinocellia Handlirsch, 1910, Archiinocellia oligoneura Handlirsch, 1910 from Horsefly River (British Columbia, Canada), and A. protomaculata (Engel, 2011), comb. nov., from the Green River Formation (Colorado, United States of America) are redescribed. Archiinocellia is assigned to Raphidiidae, sit. nov. The apparent absence of sclerotized gonocoxites 9 in the Archiinocellia protomaculata male is probably plesiomorphic at the family level. As some modern snakeflies do not require a cold interval to complete their development and Eocene Inocelliidae and Raphidiidae lived in regions of warm winters (especially A. protomaculata), adaptation to cold winters in many modern snakeflies is a post-Eocene phenomenon. Eocene Raphidiidae of Europe (Priabonian) differ greatly from those of North America (Ypresian and Priabonian). This pattern might reflect dispersal in either direction or ranges established prior to continental separation. Eocene Inocelliidae of Europe (Priabonian), however, are more similar to those of North America (Ypresian and Lutetian). 

New Protosmylinae (Neuroptera: Osmylidae) from the early Eocene of western North America, with taxonomic remarks

Zootaxa ◽  
2021 ◽  
Vol 4980 (1) ◽  
pp. 142-156
Author(s):  
VLADIMIR N. MAKARKIN ◽  
S. BRUCE ARCHIBALD ◽  
ROLF W. MATHEWES
Keyword(s):  
North America ◽  
Hind Wing ◽  
Late Eocene ◽  
Early Eocene ◽  
Western North America ◽  
Green River ◽  
Incertae Sedis ◽  
Three New Species ◽  
Okanagan Highlands ◽  
Provincial Park

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. 

Salamander tracks (Ambystomichnus?) from the Cathedral Bluffs tongue of the Wasatch Formation (Eocene), northeastern Green River Basin, Wyoming

2001 ◽  
Vol 75 (4) ◽  
pp. 901-904 ◽  
Author(s):  
John R. Foster
Keyword(s):  
United States ◽  
Skeletal Remains ◽  
Ellesmere Island ◽  
Green River Formation ◽  
Western United States ◽  
The Arctic ◽  
Early Eocene ◽  
Green River Basin ◽  
Green River ◽  
Vertebrate Tracks

Vertebrate tracks are comparatively rare in Tertiary deposits of the western United States. Unlike the deposits of the Mesozoic in this region, in which each formation often has several dozen known tracksites, there are only a few known sites in Paleocene units of the region (Lockley and Hunt, 1995), and though the Eocene Green River Formation contains relatively numerous tracks, especially those of birds, there are only a few taxa represented. The occurrence of amphibian tracks in the Eocene Wasatch Formation is therefore of interest, not only in that it adds to the known ichnological record of the Tertiary of the western United States but also in that the tracks indicate the presence of an otherwise under-represented member of the vertebrate paleofauna of the time. Skeletal remains of amphibians are present but not common in many Tertiary formations of the western United States, and remains of large salamanders are rare. Only the large caudate Piceoerpeton is known from the Tiffanian and Clarkforkian of Montana and Wyoming (Naylor and Krause, 1981), and its only Wasatchian occurrence is at Ellesmere Island, north of the Arctic Circle. The tracks described here appear to represent a nearly Piceoerpeton-sized salamander in the lacustrine shoreline deposits of the early Eocene Wasatch Formation of southwestern Wyoming.

scholarly journals An Exceptionally Preserved Specimen From the Green River Formation Elucidates Complex Phenotypic Evolution in Gruiformes and Charadriiformes

2020 ◽  
Vol 8 ◽  
Author(s):  
Grace Musser ◽  
Julia A. Clarke
Keyword(s):  
Fossil Record ◽  
Phylogenetic Analyses ◽  
Divergence Time ◽  
Axial Skeleton ◽  
Green River Formation ◽  
New Taxon ◽  
Early Eocene ◽  
Phenotypic Evolution ◽  
Green River ◽  
Partial Skeleton

The stem lineage relationships and early phenotypic evolution of Charadriiformes (shorebirds) and Gruiformes (rails, cranes, and allies) remain unresolved. It is still debated whether these clades are sister-taxa. New phylogenetic analyses incorporating Paleogene fossils have the potential to reveal the evolutionary connections of these two speciose and evolutionarily critical neoavian subclades. Although Gruiformes have a rich Paleogene fossil record, most of these fossils have not been robustly placed. The Paleogene fossil record of Charadriiformes is scarce and largely consists of fragmentary single elements. Only one proposed Eocene charadriiform-like taxon, Scandiavis mikkelseni of Denmark, is represented by a partial skeleton. Here, we describe a new species from the early Eocene Green River Formation of North America comprising a partial skeleton and feather remains. Because the skeleton lacks the pectoral girdle and forelimbs as in S. mikkelseni, only features of the skull, axial skeleton, and hind limb are available to resolve the phylogenetic placement of this taxon. These anatomical subregions initially showed features seen in Charadriiformes and Gruiformes. To assess placement of this taxon, we use a matrix consisting of 693 morphological characters and 60 taxa, including S. mikkelseni and the oldest known charadriiform taxa represented by single elements. These more fragmentary records comprise two distal humeri from the earliest Eocene Naranbulag Formation of Mongolia and the early Eocene Nanjemoy Formation of Virginia. Our phylogenetic analyses recover the new taxon and S. mikkelseni alternatively as a charadriiform or as a stem-gruiform; placement is contingent upon enforced relationships for major neoavian subclades recovered by recent molecular-based phylogenies. Specifically, when constraint trees based on results that do not recover Charadriiformes and Gruiformes as sister-taxa are used, the new taxon and S. mikkelseni are recovered within stem Gruiformes. Both Paleogene fossil humeri are consistently recovered within crown Charadriiformes. If placement of these humeri or the new taxon as charadriiforms are correct, this may indicate that recent divergence time analyses have underestimated the crown age of another major crown avian subclade; however, more complete sampling of these taxa is necessary, especially of more complete specimens with pectoral elements.

scholarly journals Aerodynamic reconstruction of the primitive fossil bat Onychonycteris finneyi (Mammalia: Chiroptera)

2019 ◽  
Vol 15 (3) ◽  
pp. 20180857 ◽  
Author(s):  
Lucila I. Amador ◽  
Nancy B. Simmons ◽  
Norberto P. Giannini
Keyword(s):  
Aspect Ratio ◽  
Rapid Evolution ◽  
Fold Increase ◽  
Green River Formation ◽  
Developmental Changes ◽  
Early Eocene ◽  
Wing Loading ◽  
Green River ◽  
Aerodynamic Efficiency ◽  
Extinct Species

Bats are the only mammals capable of powered flight. One of the oldest bats known from a complete skeleton is Onychonycteris finneyi from the Early Eocene (Green River Formation, Wyoming, 52.5 Ma). Estimated to weigh approximately 40 g, Onychonycteris exhibits the most primitive combination of characters thus far known for bats. Here, we reconstructed the aerofoil of the two known specimens, calculated basic aerodynamic variables and compared them with those of extant bats and gliding mammals. Onychonycteris appears in the edges of the morphospace for bats, underscoring the primitive conformation of its flight apparatus. Low aerodynamic efficiency is inferred for this extinct species as compared to any extant bat. When we estimated aerofoil variables in a model of Onychonycteris excluding the handwing, it closely approached the morphospace of extant gliding mammals. Addition of a handwing to the model lacking this structure results in a 2.3-fold increase in aspect ratio and a 28% decrease in wing loading, thus greatly enhancing aerodynamics. In the context of these models, the rapid evolution of the chiropteran handwing via genetically mediated developmental changes appears to have been a key transformation in the hypothesized transition from gliding to flapping in early bats.

Oldest new genus of Myrmeleontidae (Neuroptera) from the Eocene Green River Formation

Zootaxa ◽  
2017 ◽  
Vol 4337 (4) ◽  
pp. 540 ◽  
Author(s):  
VLADIMIR N. MAKARKIN
Keyword(s):  
New Genus ◽  
Green River Formation ◽  
Wing Venation ◽  
Early Eocene ◽  
Green River ◽  
The Family

Epignopholeon sophiae gen. et sp. nov. (Neuroptera: Myrmeleontidae) is described from the early Eocene of the Green River Formation (Colorado, U.S.A.). It represents the oldest confident record of the family. The new genus is remarkable in that tergite 7 of the female is much shorter than its long sternite 7. The preserved wing venation shows that the genus belongs to the subfamily Myrmeleontinae, and most probably to the tribe Gnopholeontini. The discovery of this species is consistent with estimations of relatively dry and warm conditions during deposition of the upper Parachute Creek Member of the Green River Formation. 

Sign in / Sign up

Export Citation Format

Share Document