A5007958522- Paleontology and Evolutionary Biology
- Evolution and Paleontology Studies
- Ichthyology and Marine Biology
- Paleontology and Stratigraphy of Fossils
- Amphibian and Reptile Biology
- Geological and Geophysical Studies
- Turtle Biology and Conservation
- Fish biology, ecology, and behavior
- Genetic diversity and population structure
- Plant Ecology and Soil Science
- Forensic and Genetic Research
- Wildlife Ecology and Conservation
- Climate Change, Adaptation, Migration
- Ecology and biodiversity studies
- Innovations in Educational Methods
- Infectious Diseases and Mycology
- Botany and Plant Ecology Studies
- Innovative Teaching Methods
- Evaluation of Teaching Practices
- Fossil Insects in Amber
- Marine and environmental studies
- Morphological variations and asymmetry
- Geological and Geochemical Analysis
- Pacific and Southeast Asian Studies
- Avian ecology and behavior
Idaho State University
2021-2025
Centro Científico Tecnológico - Patagonia Norte
2023
John Wiley & Sons (United States)
2023
Liechtenstein Institute
2023
Hudson Institute
2023
University of Washington
2013-2021
Burke Museum of Natural History and Culture
2013-2021
Field Museum of Natural History
2017-2021
Denver Museum of Nature and Science
2019
Texas Tech University
2019
Millerettidae are a group of superficially lizard-like Permian stem reptiles originally hypothesized as relevant to the ancestry reptile crown group, and particularly lepidosaurs archosaurs. Since advent cladistics, millerettids have typically been considered be more distant relatives earliest-diverging parareptiles therefore outside ‘Eureptilia’. Despite this cladistic consensus, some conspicuous features millerettid anatomy invite reconsideration their relationships. We provide detailed...
In addition to their devastating effects on global biodiversity, mass extinctions have had a long-term influence the history of life by eliminating dominant lineages that suppressed ecological change. Here, we test whether end-Permian extinction (252.3 Ma) affected distribution tetrapod faunas within southern hemisphere and apply quantitative methods analyze four components biogeographic structure: connectedness, clustering, range size, endemism. For all components, detected increased...
Abstract The fossil reptile Milleretta holds a prominent role in phylogenetic analyses of early relationships. It has often been used as the sole marker for anatomically diverse middle to late Permian Millerettidae, clade that hypothesized earliest diverging parareptiles and therefore only distantly related crown group. However, anatomy remains incompletely documented, presenting an obstacle studies evolution. We re-examine cranial rubidgei using synchrotron micro-computed tomography two...
ABSTRACT Recent discoveries have shown that non-dinosaurian dinosauromorphs were morphologically diverse, globally distributed, and a stratigraphic range extending into the Upper Triassic. Silesauridae, sister group to Dinosauria, contains at least seven species. Here we describe Lutungutali sitwensis, gen. et sp. nov., first silesaurid from upper portion of Ntawere Formation Luangwa Basin, Zambia. The has been correlated with subzone C Cynognathus Assemblage Zone Karoo Basin in South Africa...
The two vertebrate fossil assemblages from the ?Middle Triassic Ntawere Formation have been known since 1960s, but little new work has done description of novel taxa in 1960s and 1970s. Three recent field seasons increased diversity upper assemblage expanded biostratigraphic connections between lower fossiliferous basins across southern Pangea. contains hybodontoid sharks, ptychoceratodontid lungfish, large- small-bodied stereospondyl amphibians (Cherninia, 'Stanocephalosaurus,'...
The late Palaeozoic is a pivotal period for the evolution of terrestrial ecosystems. Generalised warming and aridification trends resulted in profound floral faunal turnover as well increased levels endemism. patchiness well-preserved, Permian ecosystems, however, complicates attempts to reconstruct coherent, global scenario. In this paper, we provide new reconstruction Bletterbach Biota (Southern Alps, NE Italy), which constitutes unique, low-latitude record Lopingian life on land. We also...
Abstract Recumbirostra is a clade of heavily modified, superficially lizard‐like tetrapods that were originally interpreted as ‘microsaurian lepospondyls’ unrelated to the amniote crown. However, recent work has placed within Reptilia, based on many similarities between braincase and postcranium recumbirostrans with early reptiles. Here, Permian hapsidopareiid recumbirostran Hapsidopareion lepton re‐described using high‐resolution μCT data three individuals across distinct ontogenetic...
Click to increase image sizeClick decrease size ACKNOWLEDGMENTSOur research in Zambia has been supported by the National Geographic Society (CRE 8571-088 J.S.S., CRE 8961-11 C.A.S.), with additional support from The Grainger Foundation and Field Museum/IDP, Inc. African Partner's Program (to K.D.A.), NSF EAR-1337569 EAR-1337291 K.D.A.). B.R.P. was a Graduate Research Fellowship. We thank K. Mwamulowe J. Museba (NHCC) for assistance arranging carrying out field work. Fossil preparation...
Cynognathus crateronotus is a species of large carnivorous cynodont, first named and best known from the Triassic Burgersdorp Formation (Beaufort Group, Karoo Basin) South Africa. Fossils genus have also been reported upper Fremouw Antarctica, Upper Omingonde Namibia, Río Seco de la Quebrada Argentina. Without associated cranial material, however, distinguishing postcrania that closely related cynognathian, Diademodon tetragonus, has proven difficult. Here we provide more comprehensive...
ABSTRACTRenewed field work in the Beardmore Glacier region of Antarctica has led to a new collection tetrapod fossils from upper member Fremouw Formation near Peak. This locality records sedimentary environment remarkably similar that preserved at Gordon Valley, only other known preserve Cynognathus Assemblage Zone–equivalent taxa Antarctica. Fossil bones are generally disarticulated and mixed with logs reworked mudrock clasts, forming an intraformational channel-lag conglomerate. To date,...
Living reptiles include more than 20,000 species with disparate ecologies. Direct anatomical evidence from Neodiapsida, which includes the reptile crown-group Sauria and its closest extinct relatives, shows that this diversity originates a single common reptilian ancestor lived some 255 million years ago in Paleozoic. However, evolutionary assembly of crown traits is poorly understood due to lack anatomically close outgroups Neodiapsida. We present substantially revised phylogenetic...
The Permian-Triassic mass extinction (PTME) was one of the transformative events Phanerozoic, marked by extinction, post-Permian transformation surviving ecosystems, and formation new communities. South African Karoo Basin has served as primary source data on terrestrial component these events, but its global applicability remains poorly known. Here, we compare communities with those from Luangwa Ruhuhu basins Zambia Tanzania, respectively, analyzing their functional structures simulating...
Abstract Use of quantitative morphological methods in biology has increased with the availability 3D digital data. Rotated orientation patch count (OPCr) leverages such data to quantify complexity an animal's feeding surface, and previously been used analyze how tooth signals diet squamates, crocodilians, mammals. These studies show a strong correlation between dental diet. However, dietary prediction using this technique not tested on structures edentulous (toothless) taxa. This study is...
We report a complete left fourth metatarsal collected from rocks of the Upper Cretaceous (Campanian) "El Gallo" Formation exposed along Pacific Ocean near El Rosario, Baja California, México.The IV was part an arctometatarsalian metatarsus, as evidenced by deep medial notch proximally and extensive articulation for III.This condition, with U-shape proximal end, supports identification tyrannosauroid.It is assigned to Tyrannosauridae based on features posterior surface shaft, but finer...
The mammalian tusk is a unique and extreme morphotype among modern vertebrate dentitions. Tusks—defined here as ever-growing incisors or canines composed of dentine—evolved independently multiple times within mammals yet have not evolved in other extant vertebrates. This suggests that there feature specific to facilitates the evolution this specialized dentition. To investigate what may underpin tusks, we histologically sampled tusks dicynodont therapsids: earliest iteration only...
Temnospondyl specimens collected recently in the Middle-?Late Triassic of Ruhuhu (Tanzania) and Luangwa (Zambia) rift basins are described figured. They attributed to cf. Cherninia megarhina (Chernin & Cosgriff, 1975), Mastodonsauroidea indet., Stereospondyli Stereospondyli, as well intercentra small adult individual(s) which may belong a new taxon. Although fragmentary, this material allows taxonomic updates temnospondyl assemblages Tanzania Zambia documents an interesting phylogenetic...
The late Palaeozoic is a pivotal period for the evolution of terrestrial ecosystems.Generalised warming and aridification trends resulted in profound floral faunal turnover as well increased levels endemism.The patchiness well-preserved, Permian ecosystems, however, complicates attempts to reconstruct coherent, global scenario.In this paper, we provide new reconstruction Bletterbach Biota (Southern Alps, NE Italy), which constitutes unique, low-latitude record Lopingian life on land.We also...