Aerugoamnis paulus, New Genus and New Species (Anura: Anomocoela): First Reported Anuran from the Early Eocene (Wasatchian) Fossil Butte Member of the Green River Formation, Wyoming

2013 ◽  
Vol 81 (4) ◽  
pp. 295-309 ◽  
Author(s):  
Amy C. Henrici ◽  
Ana M. Báez ◽  
Lance Grande
2016 ◽  
Vol 90 (5) ◽  
pp. 981-1011 ◽  
Author(s):  
Gregg F. Gunnell ◽  
John-Paul Zonneveld ◽  
William S. Bartels

AbstractFieldwork conducted in the Wasatch Formation in and around Fossil Butte has yielded a diverse assemblage of early Eocene vertebrates. Fossil vertebrates are distributed through three discrete stratigraphic intervals within the uppermost 180 m of the main body of the Wasatch Formation underlying the Green River Formation. These assemblages were derived primarily from fluvial overbank mudstone units overprinted with variably well-developed paleosols. The lowest (20 m) and highest (60 m) sections are characterized by less mature and more hydromorphic paleosols, whereas the middle section (100 m) is typified by more mature paleosols and more abundant channel sandstones.The combined assemblages contain at least 46 species of mammals. Faunal characteristics include high abundances of equid perissodactyls and a relatively high abundance and diversity of notharctines primates, an apparent absence of omomyid primates, relatively high rodent diversity, and relatively diverse and abundant artiodactyls. One new genus (Eoictopsnew genus) and three new species (Eoictops novacekinew species,Palaeosinopa lacusnew species, and ?Notoparamys blochinew species) are included in the Fossil Butte assemblage. Also recorded are late occurrences of two hyopsodontid condylarths and an early occurrence of a rare phenacodontid condylarth. The relatively high abundances of equids and notharctines suggest that vertebrate samples were derived from relatively open paleohabitats that included forested areas along water courses.All three assemblages contain characteristic Lysitean (Wasatchian biochron Wa-6) elements, but the occurrence of the palaeotheriid perissodactylLambdotheriumin the uppermost horizon indicates a Lostcabinian (Wa-7) age for at least the top of the Wasatch Formation. The overlying predominantly fish-bearing Fossil Butte Member of the Green River Formation also containsLambdotheriumand is therefore Wa-7 in age as well.


Zootaxa ◽  
2017 ◽  
Vol 4337 (4) ◽  
pp. 540 ◽  
Author(s):  
VLADIMIR N. MAKARKIN

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. 


Zootaxa ◽  
2017 ◽  
Vol 4226 (4) ◽  
pp. 594 ◽  
Author(s):  
VLADIMIR N. MAKARKIN

Xenoberotha angustialata gen. et sp. nov. (Neuroptera: Berothidae) is described from the early Eocene of the Parachute Creek Member of the Green River Formation (U.S.A., Colorado). It is assigned to Berothinae as an oldest known member of the subfamily based on the presence of scale-like setae on the foreleg coxae. Distal crossveins of the fourth (outer) gradate series which are located very close to the wing margin in Xenoberotha gen. nov. is a character state previously unknown in Berothinae. 


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4950 ◽  
Author(s):  
N. Adam Smith ◽  
Aj M. DeBee ◽  
Julia A. Clarke

Zygodactylidae are an extinct lineage of perching birds characterized by distinct morphologies of the foot and wing elements. Although the clade has a complex taxonomic history, current hypotheses place Zygodactylidae as the sister taxon to Passeriformes (i.e., songbirds). Given the rather sparse fossil record of early passeriforms, the description of zygodactylid taxa is important for inferring potentially ancestral states in the largest radiation of living birds (i.e., the ∼6,000 species of extant passeriforms). Despite the exceptional preservation of many specimens and considerable species diversity in Zygodactylidae, the relationships among species have not been previously evaluated in a phylogenetic context. Herein, we review the fossil record of Zygodactylidae from North America and describe five new well-preserved fossils from the early Eocene Green River Formation of Wyoming. Two specimens are identified as representing a new species and the first records of the taxonZygodactylusoutside Europe. Anatomical comparisons with previously named taxa and the results of phylogenetic analysis including newly described specimens and previously named zygodactylid taxa provide the first hypothesis of the species-level relationships among zygodactylids. The monophyly of Zygodactylidae is supported in these new analyses. However, the monophyly ofPrimozygodactylusand the taxonomic distinction betweenZygodactylusandEozygodactylusremain unresolved and would likely benefit from the description of additional specimens.


Zootaxa ◽  
2005 ◽  
Vol 1046 (1) ◽  
pp. 1 ◽  
Author(s):  
STORRS L. OLSON ◽  
HIROSHIGE MATSUOKA

Four additional specimens from the Green River Formation of Wyoming are referred to the Eocene frigatebird Limnofregata azygosternon Olson, originally described from a nearly complete skeleton and two partial paratypes. Two skulls with mandibles and a partial postcranial skeleton are described as a new species, Limnofregata hasegawai, characterized by much larger size and a proportionately longer bill. One of the referred specimens of L. azygosternon is from Eocene Lake Gosiute, whereas all of the other specimens of Limnofregata are from Fossil Lake. The species of Limnofregata would have taken advantage of frequent periodic dieoffs of fish in the Green River lakes. Geological and climatic factors that may have influenced the paleoecology, distribution, and size variation in frigatebirds in the Cenozoic are reviewed.


PalZ ◽  
2017 ◽  
Vol 92 (1) ◽  
pp. 35-63 ◽  
Author(s):  
Tamara Spasojevic ◽  
Gavin R. Broad ◽  
Andrew M. R. Bennett ◽  
Seraina Klopfstein

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.


2001 ◽  
Vol 75 (4) ◽  
pp. 901-904 ◽  
Author(s):  
John R. Foster

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.


2020 ◽  
Vol 8 ◽  
Author(s):  
Grace Musser ◽  
Julia A. Clarke

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.


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