[dinosaur] New Mexico chasmosaurine transitional evolutionary forms (free pdf)

Ben Creisler
[email protected]

A new preprint paper:

Denver W Fowler & Elizabeth A Freedman Fowler (2019)
Transitional evolutionary forms and stratigraphic trends in chasmosaurine
ceratopsid dinosaurs : evidence from the Campanian of New Mexico.
BioRxiv (advance online publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1101_854794&d=DwIBaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=w1g7y92pYOfopgD68xpfGXAcVknJrFYkhR-_Wm5eZwE&s=zFPax-o3oVB2gbswa4mIM8YtCvAiztNgxhG-0fH0f7U&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.biorxiv.org_content_10.1101_854794v1&d=DwIBaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=w1g7y92pYOfopgD68xpfGXAcVknJrFYkhR-_Wm5eZwE&s=Caz-SUPXIBkBh41SqmcNxnZ9ZUvStgEpFhZ0vQhIUS4&e= 

Free pdf:
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.biorxiv.org_content_biorxiv_early_2019_11_25_854794.full.pdf&d=DwIBaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=w1g7y92pYOfopgD68xpfGXAcVknJrFYkhR-_Wm5eZwE&s=zvwwIkeZtuRcmB-gFf1OBvGKMyKR2p3w4IQhRoQ_vj8&e= 


Three new chasmosaurines from the Kirtland Formation (~75.0 - 73.4 Ma), New
Mexico, form morphological and stratigraphic intermediates between
Pentaceratops (~74.7 - 75Ma, Fruitland Formation, New Mexico) and
Anchiceratops (~72 - 71Ma, Horseshoe Canyon Formation, Alberta). The new
specimens exhibit gradual enclosure of the parietal embayment that
characterizes Pentaceratops, providing support for the phylogenetic
hypothesis that Pentaceratops and Anchiceratops are closely related. This
stepwise change of morphologic characters observed in chasmosaurine taxa
that do not overlap stratigraphically is supportive of evolution by
anagenesis. Recently published hypotheses that place Pentaceratops and
Anchiceratops into separate clades are not supported. This phylogenetic
relationship demonstrates unrestricted movement of large-bodied taxa
between hitherto purported northern and southern provinces in the Late
Campanian, weakening support for the hypothesis of extreme faunal
provincialism in the Late Cretaceous Western Interior.