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Ecometric analyses use the relationships between functional traits and the environment at the community level to quantitatively estimate past climatic and environmental variables at fossil sites. Hypsodonty (tooth crown height) in North American rodent and lagomorph (Glires) communities is correlated with mean annual temperature and annual precipitation. Here, we examine the community hypsodonty of African Glires to test if this relationship translates to a continent with more extreme climates and to quantify paleoprecipitation at important fossil sites. Categorical hypsodonty values were gathered from the literature and museum collections for 94 modern African taxa (88%). We used maximum likelihood to model the ecometric relationship between hypsodonty and annual precipitation. We then produced trait-based estimates of paleoprecipitation for 26 well sampled fossil localities from eastern Africa over the last 5.7 Ma. We confirmed other regional studies by identifying increasing aridity and decreasing annual precipitation (824 mm to 480 mm) in the Late Miocene of Kenya. From the Ethiopian Shungura Formation, we estimated temporal fluctuations in precipitation that correspond with the presence or absence of paleolakes and rivers. Small mammal community hypsodonty illustrates that east African communities have converged towards mesodont means and high standard deviations in response to climate change.
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Osteology and neuroanatomy of a phasianid (Aves: Galliformes) from the Miocene of Nebraska
Abstract Tetraoninae (grouse) and Meleagridinae (turkeys) are conspicuous representatives of the modern North American avifauna. The pre-Pleistocene fossil record of these clades has historically been limited to fragmentary remains, in some cases contributing to confusion rather than improving our understanding of how these charismatic landfowl evolved. We report an exquisitely preserved partial skeleton representing a new species of Late Miocene phasianid from the Ash Hollow Formation of Nebraska. Centuriavis lioae n. gen. n. sp. is a phasianid species close in size to modern sage-grouse that diverged prior to the grouse-turkey split, and thus offers insight into the early history of this radiation. The cranial endocast resembles other North American phasianids and differs from odontophorids in exhibiting a strongly projected Wulst bordered by a well-defined vallecula. Phylogenetic analyses indicate that Centuriavis lioae forms a clade with Tetraoninae, Meleagridinae, and Pucrasia macrolopha (Koklass pheasant). The new fossil species provides a Late Miocene minimum calibration for the divergence of these extant taxa from other Galliformes and supports the hypothesis of a single dispersal from Asia to North America by a lineage that later gave rise to grouse and turkeys. UUID: https://zoobank.org/34ecda2f-f2f2-4c92-a82f-292e23cf2da1
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- Award ID(s):
- 1655736
- PAR ID:
- 10444833
- Date Published:
- Journal Name:
- Journal of Paleontology
- Volume:
- 97
- Issue:
- 1
- ISSN:
- 0022-3360
- Page Range / eLocation ID:
- 223 to 242
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1017/jpa.2022.80
