Cranial Polymorphism and Systematics of Miocene and Living Alligator in North America

@inproceedings{Whiting2016CranialPA,
  title={Cranial Polymorphism and Systematics of Miocene and Living Alligator in North America},
  author={Evan T. Whiting and David W Steadman and Kent A Vliet},
  year={2016}
}
Abstract We examined the osteology of Neogene Alligator, with a focus on fossils from the late Miocene (~8–7 million years ago [Ma]) Moss Acres Racetrack locality in Marion County, Florida, USA. These fossils have been referred previously to Alligator cf. A. mefferdi (early late Miocene, ~12–10 Ma, Nebraska), an extinct species that we and others have found to be lacking autapomorphic characters. Furthermore, numerous cranial polymorphisms, previously regarded as diagnostic autapomorphies or… 
Redescription and phylogenetic affinities of the caimanine Eocaiman cavernensis (Crocodylia, Alligatoroidea) from the Eocene of Argentina
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A reassessment of E. cavernensis is presented, based on first‐hand examination and micro‐computed tomography of the holotype, and some aspects of its morphology are reinterpreted, providing evidence for a monophyletic Eocaiman genus within Caimaninae, even though some highly incomplete taxa represent significant sources of phylogenetic instability.
A new caimanine (Crocodylia, Alligatoroidea) species from the Solimões Formation of Brazil and the phylogeny of Caimaninae
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A phylogenetic analysis of Eusuchia showed the new Caimanine pachytemporalis as sister to Purussaurus, which allows discussion about the evolution of gigantism in the Acresuchus-Purussaurus clade, which reveals several characters that may be related to giganism.
Neogene Crocodylians from the Central Great Plains: Spatiotemporal Histories and Relationships with Regional Climatic and Environmental Changes
ABSTRACT Crocodylian fossils are well documented from Upper Cretaceous and lower to middle Paleogene deposits in the mid-high latitudes of the Western Interior, whereas the only extant North American
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TLDR
Ranges of variation in modern species require a thorough re-evaluation, and the authors may have to revisit previous perceptions of past crocodyliform diversity, rates of evolution or anagenetic lineages in stratigraphic succession.
The Lapara Creek Fauna: Early Clarendonian of south Texas, USA
  • S. May
  • Environmental Science, Geology
    Palaeontologia Electronica
  • 2019
The Lapara Creek Fauna includes a large collection of fossil vertebrates obtained by the State-Wide Paleontologic-Mineralogic Survey in Texas (1939–1941) under the direction of the Bureau of Economic
Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem
TLDR
A new morphological dataset for Crocodylia is presented based on a critical reappraisal of published crocodylian character data matrices and extensive firsthand observations of a global sample of croc Codylians, which robustly recover Gavialis as more closely related to Tomistoma than to other extant cro codylians for the first time based on morphology alone.
SOME THOUGHTS ON INTERSPECIFIC MANDIBULAR MORPHOLOGY IN FOSSIL AND MODERN ALLIGATOR
TLDR
The genus Alligator has historically been used for nearly any blunt-snouted (brevirostrine) crocodylomorph and has been greatly constrained in its modern application via Brochu, 1999 and 2004, such that species within the genus possess the following shared osteological traits.
Spatiotemporal palaeodiversity patterns of modern crocodiles (Crocodyliformes: Eusuchia)
TLDR
These estimates reveal complex spatiotemporal palaeodiversity patterns, in which two maxima can be detected: the first during the Palaeocene and the second, which is also the biggest, in the middle-late Miocene.
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References

SHOWING 1-10 OF 30 REFERENCES
Systematics and Biogeography of Crocodylians from the Miocene of Panama
TLDR
A cladistic analysis of 32 alligatorid and three outgroup taxa resulted in 1210 equally most parsimonious cladograms, all of which suggest that Culebrasuchus mesoamericanus, gen. et sp.
First Fossil Alligator from the Late Eocene of Nebraska and the Late Paleogene Record of Alligators in the Great Plains
TLDR
Results from a cladistic analysis of 28 alligatoroid species using 181 morphological characters support the identification of the new specimens as representing the most basally divergent taxon within Alligator, suggesting that they likely represent A. prenasalis, but a lack of diagnostic features in the Nebraska specimens prevents a definitive assignment to this species.
Phylogenetics, Taxonomy, and Historical Biogeography of Alligatoroidea
TLDR
Parsimony analysis of 164 discrete morphological characters supports several previous hypotheses based on morphology and molecules that Alligatoroidea is a monophyletic alligatoroid lineage and the paraphyly of “Allognathosuchus” is indicated.
The Late Cretaceous alligatoroid Brachychampsa montana (Crocodylia) : new material and putative relationships. American Museum novitates ; no. 3116
TLDR
Preliminary comparisons suggest that Brachychampsa and its sister taxon Alberto champsa langstoni form a natural group with all alligatoroids except Diplocynodon hantoniensis, but there is no evidence placing the species within the Alligatoridae.
MORPHOLOGY AND SYSTEMATICS OF TWO MIOCENE ALLIGATORS FROM FLORIDA, WITH A DISCUSSION OF ALLIGATOR BIOGEOGRAPHY
TLDR
Cranial and postcranial remains from Alligator olseni White and Alligator cf.
ALLIGATORINE PHYLOGENY AND THE STATUS OF ALLOGNATHOSUCHUS MOOK, 1921
TLDR
A revised phylogenetic analysis supports multiple dispersal events of alligatorines from North America to Eurasia, and suggests that the cranial anatomy thought to distinguish forms such as Allognathosuchus is plesiomorphic at the level of Alligatoridae.
Tropical and western influences in vertebrate faunas from the Pliocene and Pleistocene of Florida
Fossil Kinosternidae from the Oligocene and Miocene of Florida, USA
Kinosternid remains are generally rare through the Oligocene and Miocene. Fossil material from eight Florida localities is presented here. Specimens discussed include the latest and most southeastern
Phylogenetic relationships of Necrosuchus ionensis Simpson, 1937 and the early history of caimanines
TLDR
Although the authors cannot yet pinpoint the phylogenetic placement of Necrosuchus amongst caimans, it nevertheless establishes a caimanine presence in South America by the Early Palaeocene, suggesting multiple dispersal events between North and South America, even if the modern caiman assemblage is monophyletic.
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