[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Linheraptor (Dromaeosauridae) is not Tsaagan + theropod teeth from Cretaceous of China



Ben Creisler
bcreisler@gmail.com


A new 2015 issue of Vertebrata PalAsiatica is listed on the Chinese
version of the site (not on the English version) and the open-access
pdfs links are not yet provided. However, I thought I would post them
anyway. I'll update when the links and the page numbers are available.


XU Xing, Michael PITTMAN, Corwin SULLIVAN, Jonah N. CHOINIERE, TAN
Qing-Wei,  James M. CLARK, Mark A. NORELL, WANG Shuo
The taxonomic status of the Late Cretaceous dromaeosaurid Linheraptor
exquisitus and its implications for dromaeosaurid systematics.
Vertebrata PalAsiatica (advance online)
http://www.ivpp.cas.cn/cbw/gjzdwxb/pressonline/201501/t20150112_4297277.html



The dromaeosaurid Linheraptor exquisitus was named in 2010 based on a
nearly complete skeleton recovered from the Upper Cretaceous
Wulansuhai Formation at the Gate Locality, in Bayan Mandahu, western
Nei Mongol, China. However, three recent studies regarded L.
exquisitus as a subjective junior synonym of Tsaagan mangas, a
dromaeosaurid from the Upper Cretaceous Djadokhta Formation of the
Ukhaa Tolgod locality, Mongolia. Here we refute this synonymy based on
61 morphological features that distinguish L. exquisitus from T.
mangas. Many of these features are based on new observations from
previously unprepared areas of the L. exquisitus holotype, most
notably from the left lateral side of the skull. These observations
underscore and strengthen our original taxonomic separation of L.
exquisitus and T. mangas. Evidence from L. exquisitus points to an
unexpectedly complex distribution of derived osteological features
amongst dromaeosaurids, because this species possesses features that
were previously identified as autapomorphies of T. mangas or indeed of
various other dromaeosaurids. Our review demonstrates that the
proposed synonymy between L. exquisitus and T. mangas ignores many
subtle morphological variations. Increased taxonomic sampling breaks
down seemingly obvious diagnostic differences into more subtle
morphological variations, which are potentially of great importance
for fine-scale phylogenetic analyses. Rigorous quantitative methods
using continuous data represent a promising way to exploit this type
of information in future systematic studies.

===

MO Jin-You & XU Xing (2015)
Large theropod teeth from the Upper Cretaceous of Jiangxi, southern China.
Vertebrata PalAsiatica (advance online)
http://www.ivpp.cas.cn/cbw/gjzdwxb/pressonline/201501/t20150112_4297283.html


Two isolated, large theropod teeth from the Upper Cretaceous Nanxiong
Formation of Nankang County, Jiangxi Province, southern China, are
described. Their crown heights (CH) are 76 and 91 mm, respectively.
The smaller tooth is referable to the Tyrannosauridae based on its
size and sub-oval cross-section (the crown base ratio (CBR) is about
0.72). The larger tooth is moderately laterally compressed (the CBR is
about 0.47), with well defined longitudinal oriented enamel wrinkles
at the basal halves of the mesial and distal margins, probably
represents a previously unknown large theropod inhabited Asia during
the Late Cretaceous. The recovered large theropod teeth add to the
known diversity of vertebrates from the Upper Cretaceous Nanxiong
Formation, southern China.