About

Bhart-Anjan S. Bhullar is an Associate Professor of Earth & Planetary Sciences at Yale University and serves as an Associate Curator of Vertebrate Paleontology and Vertebrate Zoology at the Yale Peabody Museum of Natural History. His research focuses on vertebrate paleontology and comparative anatomy, exploring the evolutionary and developmental transformations in vertebrates. Bhullar's work encompasses a broad range of topics including the anatomy and evolution of reptiles, the dinosaur-bird transition, and the origins and persistence of the tetrapod body plan, with particular attention to limb girdles and the regionalized spine. Through his lab, he mentors postdoctoral researchers, graduate students, and undergraduates who investigate various aspects of vertebrate morphology, evolution, and functional anatomy. His research contributes to understanding the evolutionary history and functional morphology of archosaurs and other vertebrates, integrating developmental biology with paleontological data.

Research topics

• Biology
• Ecology
• Zoology
• Neuroscience
• Evolutionary biology

Selected publications

• Electronic Supplementary Material from A short-snouted “sphenosuchian” with unusual feeding anatomy demonstrates that ecological specialization occurred early in crocodylomorph evolution

  Figshare · 2026-04-03

  articleOpen accessSenior author

  specimen history, table of measurements, comparison to Hesperosuchus agilis holotype, supplementary descriptive notes, complete phylogenetic results, comparative facial measurements

  PublisherDOI

• Supplementary material from "A short-snouted “sphenosuchian” with unusual feeding anatomy demonstrates that ecological specialization occurred early in crocodylomorph evolution"

  Figshare · 2026-04-03

  otherOpen accessSenior author

  The early evolution and diversification of Crocodylomorpha is a key component of vertebrate evolution on land but is somewhat poorly understood as a result of limited data. We describe Eosphorosuchus lacrimosa gen. et sp. nov., an early crocodylomorph from the Late Triassic of Ghost Ranch, New Mexico, whose cranial anatomy is divergent from that of other early crocodylomorphs (including Hesperosuchus agilis, to which it had been tentatively assigned), featuring an unusually short and osteologically reinforced facial region. A robust upper temporal arch and prominent surangular ridge indicate the presence of well-developed superficial external adductor musculature, which is divergent relative to pseudosuchians generally. These autapomorphies suggest specialization for a powerful bite. Bayesian and maximum parsimony phylogenetic analyses find E. lacrimosa outside of an H. agilis clade, near the base of Crocodylomorpha. The specializations of E. lacrimosa therefore represent the beginnings of ecological diversification within Crocodylomorpha among animals of a similar size, predating the Late Triassic appearance of Crocodyliformes and the Jurassic radiation of mesoeucrocodylians. Coexistence in the same single-event death assemblage of E. lacrimosa and H. agilis—two small-bodied early crocodylomorphs with functionally significant anatomical differences—suggests partitioning of terrestrial carnivorous niches within the “sphenosuchian” grade.

  PublisherDOI

• Supplementary material from "A short-snouted “sphenosuchian” with unusual feeding anatomy demonstrates that ecological specialization occurred early in crocodylomorph evolution"

  Figshare · 2026-04-03

  otherOpen accessSenior author

  The early evolution and diversification of Crocodylomorpha is a key component of vertebrate evolution on land but is somewhat poorly understood as a result of limited data. We describe Eosphorosuchus lacrimosa gen. et sp. nov., an early crocodylomorph from the Late Triassic of Ghost Ranch, New Mexico, whose cranial anatomy is divergent from that of other early crocodylomorphs (including Hesperosuchus agilis, to which it had been tentatively assigned), featuring an unusually short and osteologically reinforced facial region. A robust upper temporal arch and prominent surangular ridge indicate the presence of well-developed superficial external adductor musculature, which is divergent relative to pseudosuchians generally. These autapomorphies suggest specialization for a powerful bite. Bayesian and maximum parsimony phylogenetic analyses find E. lacrimosa outside of an H. agilis clade, near the base of Crocodylomorpha. The specializations of E. lacrimosa therefore represent the beginnings of ecological diversification within Crocodylomorpha among animals of a similar size, predating the Late Triassic appearance of Crocodyliformes and the Jurassic radiation of mesoeucrocodylians. Coexistence in the same single-event death assemblage of E. lacrimosa and H. agilis—two small-bodied early crocodylomorphs with functionally significant anatomical differences—suggests partitioning of terrestrial carnivorous niches within the “sphenosuchian” grade.

  PublisherDOI

• Electronic Supplementary Material from A short-snouted “sphenosuchian” with unusual feeding anatomy demonstrates that ecological specialization occurred early in crocodylomorph evolution

  Figshare · 2026-04-03

  articleOpen accessSenior author

  specimen history, table of measurements, comparison to Hesperosuchus agilis holotype, supplementary descriptive notes, complete phylogenetic results, comparative facial measurements

  PublisherDOI

• A short-snouted ‘sphenosuchian’ with unusual feeding anatomy demonstrates that ecological specialization occurred early in crocodylomorph evolution

  Proceedings of the Royal Society B Biological Sciences · 2026-04-15

  articleOpen accessSenior author

  The early evolution and diversification of Crocodylomorpha is a key component of vertebrate evolution on land but is somewhat poorly understood as a result of limited data. We describe Eosphorosuchus lacrimosa gen. et sp. nov., an early crocodylomorph from the Late Triassic of Ghost Ranch, New Mexico, whose cranial anatomy is divergent from that of other early crocodylomorphs (including Hesperosuchus agilis, to which it had been tentatively assigned), featuring an unusually short and osteologically reinforced facial region. A robust upper temporal arch and prominent surangular ridge indicate the presence of well-developed superficial external adductor musculature, which is divergent relative to pseudosuchians generally. These autapomorphies suggest specialization for a powerful bite. Bayesian and maximum parsimony phylogenetic analyses find E. lacrimosa outside of an H. agilis clade, near the base of Crocodylomorpha. The specializations of E. lacrimosa therefore represent the beginnings of ecological diversification within Crocodylomorpha among animals of a similar size, predating the Late Triassic appearance of Crocodyliformes and the Jurassic radiation of mesoeucrocodylians. Coexistence in the same single-event death assemblage of E. lacrimosa and H. agilis-two small early crocodylomorphs with functionally significant anatomical differences-suggests partitioning of terrestrial carnivorous niches within the 'sphenosuchian' grade.

  PublisherDOI

• Phylogenetic Paradigm Shifts in Early Amniote Evolution

  Systematic Biology · 2025-12-12 · 2 citations

  articleSenior author

  The dichotomy within Amniota (mammals and reptiles) was recognized early in the history of phylogenetic systematics, and with it developed a canonical understanding of the evolutionary relationships of early-diverging clades. In recent years, the relationships of these clades have shifted dramatically among studies, which has profound effects on how researchers interpret evolutionary patterns in early amniotes. To gain a fuller understanding of the early evolution of amniotes, we compiled one of the largest amniote-wide phylogenetic datasets, including 590 fully illustrated characters and 150 taxa representing all the major clades of "pelycosaurian" stem mammals, pan-reptiles, and several outgroups. We analyzed this dataset under Bayesian and Parsimony frameworks, which resulted in different topologies, particularly among stem mammals and near-crown and within-crown Reptilia. To explore the effect sampling has on tree topology, we conducted three series of exclusion experiments, each consisting of ten analyses, each with ten fewer OTUs than the previous, as well as 26 exclusion analyses removing one major clade of early diverging amniote or individual OTU at a time. This experiment showed that taxon sampling has a major effect on early amniote tree topology, and many of the topologies we found bear striking similarities to those reported in recent publications. Furthermore, we identify and discuss several unique effects that taxon exclusion may have on phylogenies. To address poorly resolved (i.e., polytomies) and unstable portions of amniote phylogeny, where branches frequently move or dismantle depending on sampling and choice of analytical technique, we encourage more detailed anatomical work on early amniotes, particularly stem mammals, and expansion of morphological phylogenetic datasets.

  PublisherDOI

• Neuroanatomical convergence between pterosaurs and non-avian paravians in the evolution of flight

  Current Biology · 2025-11-26

  articleOpen access

  <h2>Summary</h2> The oldest known pterosaurs lived approximately 220 million years ago¹ and were already animals capable of powered flight,² an ability that later evolved independently among paravian dinosaurs, the group that includes living birds and their closest non-avian relatives.³ Flight is a complex locomotory mode that requires physiological adaptations⁴ and a dramatic transformation of the body plan, including changes in body proportions, specialized integument, and acquisition of novel neurosensory capabilities.⁵ Although pterosaurs and birds developed distinct skeletal and integumentary adaptations for flight, they are hypothesized to share neuroanatomical traits linked to aerial locomotion.⁶^,⁷^,⁸^,⁹ Here, we use geometric morphometrics and phylogenetically informed analyses to assess the origin and evolution of brain shape and size in pterosaurs, tracing the transformation from their non-volant closest relatives (lagerpetids), and compare their trajectory with that in the dinosaur-bird transition. Pterosaurs have globular brains with moderately enlarged hemispheres, more closely resembling non-avian paravians such as troodontids and <i>Archaeopteryx lithographica</i> than living birds. Whereas birds inherited their basic brain structure from their dinosaurian ancestors,¹⁰^,¹¹^,¹²^,¹³^,¹⁴^,¹⁵^,¹⁶^,¹⁷ pterosaurs share only the ventrolateralization of the optic lobe with their closest non-volant relatives, the lagerpetids. This suggests that, in contrast to the bird-line archosaurs, where exaptation may have played a central role in the stepwise assembly of the avian brain configuration, brain evolution in pterosaurs seems to have unfolded rapidly at the origin of flight.

  PublisherOA PDFDOI

• Limb proportions predict aquatic habits and soft-tissue flippers in extinct amniotes

  Current Biology · 2025-11-20

  articleSenior author
  PublisherDOI

• Reorganization of the theropod wrist preceded the origin of avian flight

  Nature · 2025-07-09 · 15 citations

  article
  PublisherDOI

• Deep-time history of primate behavior and ecology as revealed by ancestral state reconstructions

  Journal of Mammalian Evolution · 2025-05-24 · 1 citations

  articleSenior author
  PublisherDOI

Recent grants

• Dissertation Research: Origin of the modern avian locomotor system across a neglected evolutionary interval: insight from new methods and new fossils

  NSF · $21k · 2015–2016

• CAREER: Investigating the deep origin and evolution of the bird beak by synthesizing the fossil record and comparative embryology of archosaurian reptiles

  NSF · $856k · 2021–2026

Frequent coauthors

• Matteo Fabbri

  Johns Hopkins University

  78 shared

• Michael Hanson

  Planetary Science Institute

  54 shared

• Daniel J. Field

  45 shared

• Daniel Smith‐Paredes

  Yale University

  41 shared

• Gabriel S. Bever

  Johns Hopkins Medicine

  41 shared

• Laurel R. Yohe

  Planetary Science Institute

  37 shared

• Kelsey M. Jenkins

  Robert S. Peabody Museum of Archaeology

  29 shared

• David A. Burnham

  American Museum of Natural History

  27 shared

Labs

• Bhullar LabPI