Basicranial anatomy of<i>Syndyoceras cooki</i>(Artiodactyla, Protoceratidae) and the need for a reappraisal of tylopod relationships

Joeckel, R.M.; Stavas, Joseph M.

doi:10.1080/02724634.1996.10011319

Cited by 16 publications

(76 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results are in general agreement with observations by Norris (1999: 747) that the subarcuate fossa of artiodactylans is generally shallow. Joeckel andStavas (1996, drawing on Webb andTaylor, 1980) wrote that a character of Pecora ( fig. 1) is to have a reduced subarcuate fossa, which here would be equivalent to state 1.…”

Section: Character Descriptions and Character State Optimizations Chamentioning

confidence: 99%

An Anatomical and Phylogenetic Study of the Osteology of the Petrosal of Extant and Extinct Artiodactylans (Mammalia) and Relatives

O’Leary¹

2010

Bulletin of the American Museum of Natural History

107

View full text Add to dashboard Cite

Section: Character Descriptions and Character State Optimizations Chamentioning

confidence: 99%

An Anatomical and Phylogenetic Study of the Osteology of the Petrosal of Extant and Extinct Artiodactylans (Mammalia) and Relatives

O’Leary¹

2010

Bulletin of the American Museum of Natural History

107

View full text Add to dashboard Cite

“…However, cetacean workers have long used characters of the basicranium in phylogenetic analyses. Studies of artiodactyl ear morphology have been largely opportunistic, based on broken or disarticulated skull material (Hürzeler, 1936;Dechaseaux, 1967Dechaseaux, , 1969Dechaseaux, , 1974Webb and Taylor, 1980;Coombs and Coombs, 1982;Norris, 1999Norris, , 2000, but three studies have used serial sectioning (Whitmore, 1953) and computed tomographic (CT) scans (Joeckel, 1992;Joeckel and Stavas, 1996) to examine the internal anatomy of the ear region.…”

Section: Introductionmentioning

confidence: 99%

“…Hürzeler's description included a description of the hollow structures of the middle and inner ear, which he described from casts produced by filling the canals with celluloid. Recent work on the ear region of protoceratids (Joeckel and Stavas, 1996;Norris, 2000) and basal tylopods (Norris, 1999) showed that the petrosal anatomy of protoceratids resembles that of ruminants more than Tylopoda, where they have long been placed. Joeckel and Stavas (1996) noted that the derived protoceratid Syndyoceras differed in petrosal morphology from the extant camelids, as protoceratids lacked a characteristic flange on the petrosal roofing over the petrobasilar canal.…”

Section: Introductionmentioning

confidence: 99%

“…Recent work on the ear region of protoceratids (Joeckel and Stavas, 1996;Norris, 2000) and basal tylopods (Norris, 1999) showed that the petrosal anatomy of protoceratids resembles that of ruminants more than Tylopoda, where they have long been placed. Joeckel and Stavas (1996) noted that the derived protoceratid Syndyoceras differed in petrosal morphology from the extant camelids, as protoceratids lacked a characteristic flange on the petrosal roofing over the petrobasilar canal. Norris examined material of the basal tylopod taxon Bunomeryx (1999) and the basal protoceratid Leptotragulus (2000) to address this question, and showed that the periotic morphology of Bunomeryx was more similar to that of camelids, whereas Leptotragulus was clearly a basal protoceratid.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Micro–computed tomographic scanning of the ear region ofCainotherium: character analysis and implications

Theodor

2010

Journal of Vertebrate Paleontology

View full text Add to dashboard Cite

Most recent phylogenetic analyses place the Cainotheriidae within the Tylopoda, but doubts about this placement within Tylopoda have been persistent. The Cainotheriidae are well known from numerous specimens and their cranial anatomy is well documented from complete, partial and disarticulated cranial material. However, high-resolution computed tomographic (CT) scans can still provide additional data to resolve problems in the interpretation of the auditory region, and allow comparison with other tylopod and ruminant taxa. Cainotheriids share several features with various groups within the Tylopoda, including an enlarged mastoid fossa, an inflated auditory bulla filled with cancellous bone, the presence of a sinus venosus temporalis, and what has been interpreted as a large flange of the periotic enclosing the petrobasilar canal. The reconstruction of the petrobasilar canal has been difficult to interpret, as the published figures are unclear. A micro-CT scan of Cainotherium (YPM 25037) shows the morphology is more complex. The periotic shows a smaller flange that does not enclose the petrobasilar canal. The skull base shows different arrangement of bones from other artiodactyls, presumably as a result of the enlargement of the auditory bulla, which has also affected the course of the petrobasilar canal. The otic region of Cainotherium shows no resemblances to ruminants, and features of this region are consistent with the Cainotheriidae being either a sister taxon to Tylopoda + Ruminantia, or with inclusion in a tylopod grouping.

show abstract

“…These shared morphological similarities provided evidence for the idea that Camelidae was the sister group to Protoceratidae (including the primitive leptotragulines), with both groups the products of a late Eocene North American radiation of selenodont artiodactyls (Black, 1978;Webb and Taylor, 1980). However, later comparative work focused on basicranial morphology argued that protoceratids lacked obvious synapomorphies shared with Camelidae and highlighted the need for a systematic revision of North American Neogene fossil artiodactyls with cranial appendages (Joeckel and Stavas, 1996).…”

Section: Introductionmentioning

confidence: 99%

New early Miocene protoceratids (Mammalia, Artiodactyla) from Panama

Rincón

Bloch²,

MacFadden³

et al. 2015

Journal of Vertebrate Paleontology

View full text Add to dashboard Cite

ABSTRACT-Although Cenozoic protoceratid artiodactyls are known from throughout North America, species referred to the Miocene protoceratine Paratoceras are restricted to subtropical areas of the Gulf Coast and southern Mexico and tropical areas of Panama. Newly discovered fossils from the late Arikareean Lirio Norte Local Fauna, Panama Canal basin, include partial dentitions of a protoceratid remarkably similar to those of Paratoceras tedfordi from Mexico, suggesting a rapid early Miocene colonization of recently emerged tropical volcanic terrains (Las Cascadas Formation). Partial lower dentitions from the overlying shallow marine to transitional Culebra Formation (early Centenario Fauna) are here referred to Paratoceras orarius, sp. nov., based on relatively small size, shallow mandible anterior to p3, and narrow cheek teeth. New early Hemingfordian protoceratine fossils from the upper part of the Cucaracha Formation (late Centenario Fauna) include a partial male skull and several dentitions that, together with specimens previously referred to P. wardi (only known from the Barstovian of Texas), are here referred to Paratoceras coatesi, sp. nov., based on distinctly more gracile cranial ornamentation, relatively longer nasals, a smaller and wider lower p4 (relative to m1), and more bulbous lower premolars.Results from a cladistic analysis of 15 craniodental characters coded for 11 protoceratine species suggests that Paratoceras is a monophyletic clade with its origin in subtropical areas of Central America, spreading into the tropics of Panama during the early Miocene (Arikareean through Hemingfordian North American Land Mammal Ages [NALMAs]), and later inhabiting subtropical areas of the Gulf Coast during the middle-late Miocene (Barstovian through Clarendonian NALMAs).

show abstract

Basicranial anatomy ofSyndyoceras cooki(Artiodactyla, Protoceratidae) and the need for a reappraisal of tylopod relationships

Cited by 16 publications

References 15 publications

An Anatomical and Phylogenetic Study of the Osteology of the Petrosal of Extant and Extinct Artiodactylans (Mammalia) and Relatives

An Anatomical and Phylogenetic Study of the Osteology of the Petrosal of Extant and Extinct Artiodactylans (Mammalia) and Relatives

Micro–computed tomographic scanning of the ear region ofCainotherium: character analysis and implications

New early Miocene protoceratids (Mammalia, Artiodactyla) from Panama

Contact Info

Product

Resources

About