[dinosaur] Tanystropheid vertebrae from Middle Triassic Moenkopi Formation (Arizona and New Mexico) (free pdf)

Ben Creisler
[email protected]


A new paper in open access:


Kiersten K. Formoso, Sterling J. Nesbitt, Adam C. Pritchard, Michelle R.
Stocker, and William G. Parker (2019)
A long-necked tanystropheid from the Middle Triassic Moenkopi Formation
(Anisian) provides insights into the ecology and biogeography of
tanystropheids.
Palaeontologia Electronica 22.3.73: 1–15.
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.26879_988&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=nePVcRm-sB5uqoz9sznU56eUbaCFIT70J22aQkB240E&s=qbSf7-4wanjLuWe_St8BjXLygSW8if340vG_pzTATNs&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__palaeo-2Delectronica.org_content_2019_2824-2Dlong-2Dnecked-2Dmoenkopi-2Dtanystropheid&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=nePVcRm-sB5uqoz9sznU56eUbaCFIT70J22aQkB240E&s=k7hqCPc_SHQzrzL-hncNRJLUUAJMdGjTX8Kf_2s_21Y&e= 

Free pdf:
https://urldefense.proofpoint.com/v2/url?u=https-3A__palaeo-2Delectronica.org_content_pdfs_988.pdf&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=nePVcRm-sB5uqoz9sznU56eUbaCFIT70J22aQkB240E&s=ybgfNaIZNNrNRD-rKjej2ig88GkpH9oOAZpEA6uNgQc&e= 


Archosauromorphs are a diverse and successful group of reptiles that
radiated into a series of groups around the time of the end-Permian
extinction. One of these groups of archosauromorphs, tanystropheids,
consists of diverse forms, and some of the largest members of the group
possessed extremely elongated cervical vertebrae (greater than five times
longer than tall), resulting in a hyperelongate neck. These derived
tanystropheids have been found in Tethyan marine deposits of Pangaea. Four
partial cervical vertebrae from a hyperelongate-necked tanystropheid from
the Middle Triassic Moenkopi Formation of Arizona and New Mexico are
described in this paper. These cervical vertebrae are assigned to
Tanystropheidae, specifically the clade that includes the
hyperelongate-necked Tanystropheus based on character states, which include
an elongate centrum (length to height ratio of 6.2), the presence of
epipophyses, and an elongate axial centrum. The Moenkopi tanystropheid
elements were found in lower latitude fluvial sequences without any marine
influence, corresponding to western Pangaea, whereas Tanystropheus- like
tanystropheids are typically associated with marginal marine environments
in middle to high latitudes of eastern Pangaea. These fossils suggest that
hyperelongate-necked, Tanystropheus - like tanystropheids were perhaps
behaviorally bound to general semi-aquatic environments, both marine and
freshwater, due to their unique morphology. These fossils also greatly
extend the biogeographic range of large tanystropheids and increase the
anatomical diversity of tanystropheids known from North America
demonstrating that the clade persisted in a wide variety of environments
throughout the Triassic Period.

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