Eocene floras of Patagonia document biotic response to the final separation of Gondwana. The conifer genus
We review the type material of
We describe
Our results confirm the presence and indicate the survival of Sect.
Unexpected larger distribution of paleogene stem-rollers (AVES, CORACII): new evidence from the Eocene of Patagonia, Argentina
Abstract Here we present the first record of a stem-Coracii outside the Holarctic region, found in the early Eocene of Patagonia at the Laguna del Hunco locality. Ueekenkcoracias tambussiae gen. et sp. nov. consists of an incomplete right hind limb that presents the following combination of characters, characteristic of Coracii: relatively short and stout tibiotarsus, poorly developed crista cnemialis cranialis, short and wide tarsometatarsus, with the tuberositas m. tibialis cranialis located medially on the shaft, and curved and stout ungual phalanges. Although the presence of a rounded and conspicuous foramen vasculare distale and the trochlea metatarsi II strongly deflected medially resemble Primobucconidae, a fossil group only found in the Eocene of Europe and North America, our phylogenetic analysis indicates the new taxon is the basalmost known Coracii. The unexpected presence of a stem-Coracii in the Eocene of South America indicates that this clade had a more widespread distribution than previously hypothesized, already extending into the Southern Hemisphere by the early Eocene. Ueekenkcoracias tambussiae represents new evidence of the increasing diversity of stem lineages of birds in the Eocene. The new material provides novel morphological data for understanding the evolutionary origin and radiation of rollers and important data for estimates of the divergence time of the group.
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- Award ID(s):
- 1925755
- NSF-PAR ID:
- 10249586
- Date Published:
- Journal Name:
- Scientific Reports
- Volume:
- 11
- Issue:
- 1
- ISSN:
- 2045-2322
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Premise Araucaria , distributed worldwide during the Mesozoic, has a disjunct extant distribution between South America and Australasia. Fossils assigned to AustralasianAraucaria Sect.Eutacta usually are represented by isolated organs, making diagnosis difficult.Araucaria pichileufensis E.W. Berry, from the middle Eocene Río Pichileufú (RP ) site in Argentine Patagonia, was originally placed in Sect.Eutacta and later reported from the early Eocene Laguna del Hunco (LH ) locality. However, the relationship ofA. pichileufensis to Sect.Eutacta and the conspecificity of theAraucaria material among these Patagonian floras have not been tested using modern methods.Methods A. pichileufensis alongside large (n = 192) new fossil collections ofAraucaria fromLH andRP , including multi‐organ preservation of leafy branches, ovuliferous complexes, and pollen cones. We use a total evidence phylogenetic analysis to analyze relationships of the fossils to Sect.Eutacta .Results Araucaria huncoensis sp. nov. fromLH and improve the whole‐plant concept forAraucaria pichileufensis fromRP . The two species respectively resolve in the crown and stem of Sect.Eutacta .Conclusions Eutacta in South America during early Antarctic separation. The exceptionally complete fossils significantly predate several molecular age estimates for crownEutacta . The differentiation of twoAraucaria species demonstrates conifer turnover during climate change and initial South American isolation from the early to middle Eocene. -
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Abstract The middle Eocene Washakie Formation of Wyoming, USA, provides a rare window, within a single depositional basin, into the faunal transition that followed the early Eocene warming events. Based on extensive examination, we report a minimum of 27 species of carnivorous mammals from this formation, more than doubling the previous taxic count. Included in this revised list are a new species of carnivoraform, Neovulpavus mccarrolli n. sp., and up to ten other possibly new taxa. Our cladistic analysis of early Carnivoraformes incorporating new data clarified the array of middle Eocene taxa that are closely related to crown-group Carnivora. These anatomically relatively derived carnivoraforms collectively had an intercontinental distribution in North America and east Asia, exhibiting notable variations in body size and dental adaptation. This time period also saw parallel trends of increase in body size and dental sectoriality in distantly related lineages of carnivores spanning a wide range of body sizes. A new, model-based Bayesian analysis of diversity dynamics accounting for imperfect detection revealed a high probability of substantial loss of carnivore species between the late Bridgerian and early Uintan North American Land Mammal ‘Ages’, coinciding with the disappearance of formerly common mammals such as hyopsodontids and adapiform primates. Concomitant with this decline in carnivore diversity, the Washakie vertebrate fauna underwent significant disintegration, as measured by patterns of coordinated detection of taxa at the locality level. These observations are consistent with a major biomic transition in the region in response to climatically induced opening-up of forested habitats. UUID: http://zoobank.org/9162f1a6-a12c-4d55-ba1d-dc66e8cda261more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1038/s41598-020-80479-8
