A new kinosternoid from the Late Cretaceous Hell Creek Formation of North Dakota and Montana and the origin of the Dermatemys mawii lineage

  title={A new kinosternoid from the Late Cretaceous Hell Creek Formation of North Dakota and Montana and the origin of the Dermatemys mawii lineage},
  author={Georgia E. Knauss and Walter G. Joyce and Tyler R. Lyson and Dean A. Pearson},
  journal={Pal{\"a}ontologische Zeitschrift},
A nearly complete turtle shell from the Late Cretaceous (Maastrichtian) Hell Creek Formation of Slope County, North Dakota, represents the most complete remains to date of a Mesozoic kinosternoid turtle and a new species, Hoplochelys clark nov. sp. The new taxon is diagnosable from other representatives of Hoplochelys by the plesiomorphic placement of the humeral/femoral sulcus behind the hyo/hypoplastral suture and the autapomorphic development of an interrupted median (neural) keel. All six… Expand

Figures and Tables from this paper

A new species of trionychid turtle, Axestemys infernalis sp. nov., from the Late Cretaceous (Maastrichtian) Hell Creek and Lance formations of the Northern Great Plains, USA
The Late Cretaceous (Maastrichtian) Hell Creek and Lance formations in the states of North Dakota, South Dakota, Montana, and Wyoming, USA, have yielded rich remains of trionychid turtles, but theExpand
A New Baenid Turtle, Saxochelys gilberti, gen. et sp. nov., from the Uppermost Cretaceous (Maastrichtian) Hell Creek Formation: Sexual Dimorphism and Spatial Niche Partitioning within the Most Speciose Group of Late Cretaceous Turtles
ABSTRACT The uppermost Cretaceous (Maastrichtian) Hell Creek Formation in North America has yielded a diverse assemblage of fossil turtles dominated by baenids. A population of over 30 individualExpand
A New Dermatemydid (Testudines, Kinosternoidea) from the Paleocene-Eocene Thermal Maximum, Willwood Formation, Southeastern Bighorn Basin, Wyoming
Gomphochelys nanus is a stem dermatemydid that is similar to N. garmanii but differs in possessing symplesiomorphies with the Late Cretaceous—Paleocene genera Agomphus and Hoplochelys. Expand
The shell morphology of the latest Cretaceous (Maastrichtian) trionychid turtle Helopanoplia distincta
Shell remains of eight fossils referable to Helopanoplia distincta from the Hell Creek Formation of Montana and North Dakota are described that document nearly all aspects of the shell morphology of this taxon and place it as sister to the clade formed by Plastomenus thomasii and Hutchemys spp. Expand
Boremys (Testudines, Baenidae) from the Latest Cretaceous and Early Paleocene of North Dakota: An 11-Million-Year Range Extension and an Additional K/T Survivor
ABSTRACT For over a century, the baenid turtle Boremys has been recognized as being restricted to the Campanian of North America. Herein we describe new material of Boremys sp. from the Hell CreekExpand
A New Chelydroid Turtle, Lutemys warreni, Gen. Et Sp. Nov., from the Upper Cretaceous (Campanian) Kaiparowits Formation of Southern Utah
ABSTRACT A fragmentary skeleton from the Kaiparowits Formation (Upper Campanian) of southern Utah represents a new taxon of chelydroid turtle herein named Lutemys warreni. Lutemys warreni differsExpand
Allaeochelys libyca, a New Carettochelyine Turtle from the Middle Miocene (Langhian) of Libya
Abstract Fossil carettochelyine turtles are well known from the Paleogene of Europe (Allaeochelys), North America and Asia (Anosteira); however, the previously known Neogene fossil record is highlyExpand
A Review of the Fossil Record of Turtles of the Clade Pan-Kinosternoidea
Turtles of the total clade Pan-Kinosternoidea have a relatively poor fossil record that extends back to the Late Cretaceous, and a taxonomic review of the group concludes that of 42 named taxa, 27 are nomina valida, including two species of the controversial taxon Planetochelys. Expand
A new turtle from the Xiagou Formation (Early Cretaceous) of Changma Basin, Gansu Province, P. R. China
Changmachelys bohlini gen. et sp. nov., from the Lower Cretaceous Xiagou Formation, Changma Basin, north-western Gansu Province, adds to our understanding of the diversity and distribution of EarlyExpand
A Review of the Fossil Record of Turtles of the Clade Pan-Chelydridae
  • W. Joyce
  • Biology
  • Bulletin of the Peabody Museum of Natural History
  • 2016
Turtles of the total clade Pan-Chelydridae have a relatively sparse fossil record that reaches back to the Late Cretaceous (Santonian) but spread along unclear routes to Asia and Europe during the Paleocene, only to go extinct on those continents by the end of the Pliocene. Expand


Early Kinosterninae (Reptilia: Testudines) and their phylogenetic significance
The morphology of the fossil forms bridges much of the morphological gap between the extant Kinosterninae and Staurotypinae. Expand
Late Cretaceous and early Paleocene turtles of the Denver Basin, Colorado
The record of turtles in the Denver Basin spans four formations (Fox Hills, Laramie, Arapahoe, and Denver) that range from Late Cretaceous (Lancian) to early Paleocene (Puercan) in age. We recognizeExpand
Patterns of geographic variation in latest Cretaceous vertebrates: Evidence from the turtle component
Turtles are among the most widespread, abundant, and diverse fossil vertebrate groups in the latest Cretaceous. On the basis of new data from the Hell Creek Formation (North Dakota) and Lance andExpand
Phylogenetic Relationships of Mesozoic Turtles
This revised topology has important implications for the evolution of several character complexes, because it implies that the common ancestor of all living turtles must have had a partially braced brain case and a primitive trochlear mechanism. Expand
Paleocene turtle remains from South Carolina
THE TURTLE FAUNA FROM the Williamsburg Formation of the Paleocene of South Carolina is the most diverse yet known from the Paleocene of eastern North America, although this may reflect the mixedExpand
Diversity of turtles across the cretaceous/tertiary boundary in Northeastern Montana
Abstract The abundant chelonian faunas of the Hell Creek and Tullock formations of McCone and Garfield counties, Montana, span the Cretaceous/Tertiary boundary and provide a basis for assessingExpand
Megaflora of the Hell Creek and lower Fort Union Formations in the western Dakotas: Vegetational response to climate change, the Cretaceous-Tertiary boundary event, and rapid marine transgression
The Hell Creek and Fort Union Formations in southwestern North Dakota and northwestern South Dakota have yielded a diverse megaflora of 380 species from 158 quarry sites. These sites are situated inExpand
The complete mitochondrial genome of the enigmatic bigheaded turtle (Platysternon): description of unusual genomic features and the reconciliation of phylogenetic hypotheses based on mitochondrial and nuclear DNA
This study robustly determines the phylogenetic placement of Platysternon and provides a well-resolved outline of major turtle lineages, while demonstrating the significantly greater resolving power of comparing large amounts of mt sequence over that of short fragments. Expand
Lithostratigraphy of the Hell Creek Formation in North Dakota
In North Dakota, the Hell Creek Formation is a Laramide clastic wedge of primarily nonmarine strata intercalated with marine and brackish facies. The formation ranges in thickness from 100 to 60 m onExpand
Tests of turtle phylogeny: molecular, morphological, and paleontological approaches.
Branch-length analysis and independent dates from the fossil record suggest that these unresolved nodes may represent a rapid radiation of the major cryptodiran lineages 90-120 million years ago. Expand