New Basal Synapsid Supports Laurasian Origin for Therapsids

@inproceedings{Liu2009NewBS,
  title={New Basal Synapsid Supports Laurasian Origin for Therapsids},
  author={Jun Liu and Bruce S. Rubidge and Jin-ling Li},
  year={2009}
}
The distant evolutionary ancestry of mammals is documented by a rich therapsid fossil record. While sphenacodontid synapsids are considered the sister-group of therapsids, the place of origin of therapsids is an enigma, largely because of a long standing morphological and temporal gap (Olson's Gap) in their fossil record. We describe a new large predatory synapsid, Raranimus dashankouensis gen. et sp. nov., from the Middle Permian of Dashankou in China which has a unique combination of… 

A re-assessment of the oldest therapsid Raranimus confirms its status as a basal member of the clade and fills Olson’s gap

CT scanning techniques are used to digitally reconstruct the bones and trigeminal canals of the snout of Raranimus in 3D and confirm that RarAnimus shares a high number of synapomorphies with more derived therapsids and is the only theraptor known so far to display a “pelycosaur”-like maxillary canal bearing a long caudal alveolar canal that gives off branches at regular intervals.

A faunivorous early sphenacodontian synapsid with a diastema

The diagnosis of this new form, Kenomagnathus scottae gen. et sp.

A new specimen of Biseridens qilianicus indicates its phylogenetic position as the most basal anomodont

A new well-preserved basal therapsid skull from the Xidagou Formation, Middle Permian of China, is identified as Biseridens qilianicus and is found to be the most basal anomodont, which highlights separate Laurasian and Gondwanan basal anamodont clades and suggests that dicynodonts had their origins in the Gondwana clade.

Adult morphology of the therocephalian Simorhinella baini from the middle Permian of South Africa and the taxonomy, paleobiogeography, and temporal distribution of the Lycosuchidae

The skull and partial skeleton of a large therocephalian from the uppermost Tapinocephalus Assemblage Zone of South Africa is described and forms the basis for a taxonomic re-evaluation of the Lycosuchidae as well as of the geographic and stratigraphic range of the family.

The Sphenacodontid Synapsid Neosaurus cynodus, and Related Material, from the Permo-Carboniferous of France

Sphenacodontid synapsids were major components of early Permian ecosystems. Despite their abundance in the North American part of Pangaea, they are much rarer in Europe. Among the few described

New Materials of the Enigmatic Dicynodont Abajudon kaayai (Therapsida, Anomodontia) from the Lower Madumabisa Mudstone Formation, Middle Permian of Zambia

ABSTRACT Dicynodonts were one of the most diverse and abundant clades of tetrapods from the Lopingian (late Permian) to the Late Triassic. Despite their ecological and biostratigraphic importance,

A new captorhinid reptile, Gansurhinus qingtoushanensis, gen. et sp. nov., from the Permian of China

The discovery of well-preserved captorhinid materials in the Middle Permian of China allows us to determine that the new taxon, Gansurhinus qingtoushanensis, gen. et sp.

“Pelycosaur”-Grade Synapsids: Introduction

  • R. Reisz
  • Environmental Science, Geography
  • 2014
Synapsids first appear in Late Carboniferous deposits in Nova Scotia, Canada. By the latest Carboniferous, they are the dominant vertebrates in terrestrial ecosystems and exceed their sister group

Re-evaluation of the historic Canadian fossil Bathygnathus borealis from the Early Permian of Prince Edward Island

The holotype and only known specimen of Bathygnathus borealis is a partial snout with maxillary dentition of a presumed sphenacodontid from the Lower Permian (Artinskian 283–290 Ma) redbeds of Prince

Early Evolutionary History of the Synapsida

Procrustes analysis of the two best-preserved specimens of these species allowed recognition of further shape differences: M. oligocynus has a taller but narrower cranium, taller snout, temporal opening more expanded laterally, pterygoid process located more anteriorly, and smaller suborbital vacuity.

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