The Phylogeny and Classification of Tapiromorph Perissodactyls (Mammalia)

Holbrook, Luke

doi:10.1006/clad.1999.0107

Cited by 15 publications

(21 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We assign the new specimen to a new species of Pappaceras based on the stratigraphical evidence (same with Pappaceras rather than Forstercooperia in Arshantan age) and its characteristic dental morphology (see diagnosis). The comparisons of craniodental features between Pappaceras meiomenus and the earliest representatives of main groups of early rhinocerotoids, which were considered to be highly comparable as proposed by various authors78111820, are essential for the study of rhinocerotoid evolution.…”

Section: Discussionmentioning

confidence: 99%

“…In spite that P. meiomenus is close to the Late Eocene eggysodontids Proeggysodon and Guangnanodon in size (based on length of lower molar series)1831, eggysodontids differ from the latter by having complete upper premolars, large and nearly vertically oriented canines, primitively speculate incisors that vary in number (2 or 3) across different genera, and more molarized premolars3233, and the known craniodental features of eggysodontids34 are more comparable to those of rhinocerotids rather than forstercooperiines. The enigmatic genus Uintaceras was considered as the sister group of rhinocerotids for its distinctive features of anterior dentition (buccolingually compressed upper incisors with a triangular profile) and characteristics of cheek teeth and postcranial elements835. Although Holbrook and Lucas35 pointed out some cranial differences between forstercooperiines and Uintaceras , it should be noted that the reconstruction of skull of Uintaceras was mainly based on laterally compressed and distorted materials of UCMP 69722 and UW 2410.…”

Section: Discussionmentioning

confidence: 99%

“…The genus Hyrachyus is close to rhinocerotoids, but maintains a number of features primitively similar to basal tapirmorphs7. Although Hyrachyus was regarded as a rhinocerotoid genus in several recent studies789, this affinity can’t be warranted from inconsistent phylogeny9. Its taxonomy is strongly in need of revision, and whether it is a true rhinocerotoid still remains to be further explored in broader phylogenetic analyses.…”

mentioning

confidence: 99%

“…Previous phylogenetic works on early rhinocerotoids were usually not extensive, of which only a few phylogenetic studies involved forstercooperiines, and this group was commonly regarded as either a primitive member or the sister group of paraceratheriids71920, or nested within a polyphyletic assemblage of early non-hyracodontid rhinocerotoids8. The unstable phylogenetic placement of forstercooperiines may be attributed not only to incomplete morphological information of fragmentary fossils but also to the uncertainty of relationships among main groups of rhinocerotoids.…”

mentioning

confidence: 99%

“…The unstable phylogenetic placement of forstercooperiines may be attributed not only to incomplete morphological information of fragmentary fossils but also to the uncertainty of relationships among main groups of rhinocerotoids. Particularly, the hyracodontids is generally regarded as a wastebasket since Radinsky’s work81121, which encompasses all non-amynodontid and non-rhinocerotid taxa from the Eocene to Oligocene of North America, Asia and Europe. Another important unsolved issue in the evolution of early rhinocerotoids is the relationship between amynodontids and other rhinocerotoids22.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Earliest known unequivocal rhinocerotoid sheds new light on the origin of Giant Rhinos and phylogeny of early rhinocerotoids

Wang

Bai

Meng

et al. 2016

Sci Rep

View full text Add to dashboard Cite

Forstercooperiines are a group of primitive rhinocerotoids with a relatively large body size in the Eocene, and normally considered to be closely related to Giant Rhinos. Here we report a new forstercooperiine, Pappaceras meiomenus sp. nov., from the late Early Eocene Arshanto Formation, Erlian Basin, Nei Mongol, China. Pappaceras is the earliest known unequivocal rhinocerotoid, and the holotype of the new species, represented by the most complete cranium of forstercooperiines known to date, shows the earliest evidence of reduction of the first upper premolar in rhinocerotoids, and resembles paraceratheriine Juxia in basicranial features, supporting the interpretation that the forstercooperiine clade is ancestral to paraceratheriines. The new species also displays some similarities with amynodontids in craniodental structures. Phylogenetic analysis identifies P. meiomenus as a basal taxon of the monophyletic forstercooperiines. It also reveals novel phylogenetic relationships of early rhinocerotoids that indicates Uintaceras is the sister group of paraceratheriids, to which amynodontids are more closely related than to any other group of rhinocerotoids. Furthermore, the eggysodontid clade is excluded from hyracodontids and placed as the sister group of rhinocerotids. Hyracodontidae, excluding paraceratheriids and eggysodontids, is placed as the most basal group of the rhinocerotoids.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Earliest known unequivocal rhinocerotoid sheds new light on the origin of Giant Rhinos and phylogeny of early rhinocerotoids

Wang

Bai

Meng

et al. 2016

Sci Rep

View full text Add to dashboard Cite

show abstract

Interspecific variation in the tetradactyl manus of modern tapirs (Perissodactyla:Tapirus) exposed using geometric morphometrics

Maclaren

Nauwelaerts

2017

Journal of Morphology

View full text Add to dashboard Cite

The distal forelimb (autopodium) of quadrupedal mammals is a key morphological unit involved in locomotion, body support, and interaction with the substrate. The manus of the tapir (Perissodactyla: Tapirus) is unique within modern perissodactyls, as it retains the plesiomorphic tetradactyl (four-toed) condition also exhibited by basal equids and rhinoceroses. Tapirs are known to exhibit anatomical mesaxonic symmetry in the manus, although interspecific differences and biomechanical mesaxony have yet to be rigorously tested. Here, we investigate variation in the manus morphology of four modern tapir species (Tapirus indicus, Tapirus bairdii, Tapirus pinchaque, and Tapirus terrestris) using a geometric morphometric approach. Autopodial bones were laser scanned to capture surface shape and morphology was quantified using 3D-landmark analysis. Landmarks were aligned using Generalised Procrustes Analysis, with discriminant function and partial least square analyses performed on aligned coordinate data to identify features that significantly separate tapir species. Overall, our results support the previously held hypothesis that T. indicus is morphologically separate from neotropical tapirs; however, previous conclusions regarding function from morphological differences are shown to require reassessment. We find evidence indicating that T. bairdii exhibits reduced reliance on the lateral fifth digit compared to other tapirs. Morphometric assessment of the metacarpophalangeal joint and the morphology of the distal facets of the lunate lend evidence toward high loading on the lateral digits of both the large T. indicus (large body mass) and the small, long limbed T. pinchaque (ground impact). Our results support other recent studies on T. pinchaque, suggesting subtle but important adaptations to a compliant but inclined habitat. In conclusion, we demonstrate further evidence that the modern tapir forelimb is a variable locomotor unit with a range of interspecific features tailored to habitual and biomechanical needs of each species.

show abstract

Comparative osteology of early Tertiary tapiromorphs (Mammalia, Perissodactyla)

Holbrook

2001

Zoological Journal of the Linnean Society

Self Cite

View full text Add to dashboard Cite

available online at hstp;(hww.idealibrary.com on I E )r-L c @ --_ Characters of cranial and postcranial osteology provide important data for examining the interordinal relationships of mammals. Understanding variation in the cranial and postcranial skeleton is necessary for adequately representing ancestral character states for each mammalian order. This paper provides a comprehensive description and discussion of cranial and post-rsnial osteology in one of the major perissodactyl lineages, the Tapiromorpha, the lineage including the extant rliinoceroses and tapirs and their fossil relatives. Tapiromorph skeletal morphology is described, and tapiromorphs axe compared to each other, to other perissodactyls, and to a number of other eutherians.Characters of potential phylogenetic significance are emphasized. A phylogenetic analysis of tapiromorphs using cranial and postcranial osteological characters provides a number of interesting results. The data do not support slacing Homogalar and Chalicotherioidea within Tapiromorpha. The data support several novel hypotheses regarding the phylogeny of rhinocerotoids, including a close relationship between rhinocerotids and amynodontids, relative t o hyracodontids. Finally, examples of the relevance of tapiromorph osteology to understanding perissodactyl origins are discussed, particularly new interpretations of certain primitive character states for perissodactyls.

show abstract

The Phylogeny and Classification of Tapiromorph Perissodactyls (Mammalia)

Cited by 15 publications

References 33 publications

Earliest known unequivocal rhinocerotoid sheds new light on the origin of Giant Rhinos and phylogeny of early rhinocerotoids

Earliest known unequivocal rhinocerotoid sheds new light on the origin of Giant Rhinos and phylogeny of early rhinocerotoids

Interspecific variation in the tetradactyl manus of modern tapirs (Perissodactyla:Tapirus) exposed using geometric morphometrics

Comparative osteology of early Tertiary tapiromorphs (Mammalia, Perissodactyla)

Contact Info

Product

Resources

About