Open Paleo

Niobrarasaurus

Carpenter et al., 1995 nie-o-BRAHR-a-SAWR-us

Named after the Niobrara Formation of Kansas where its fossils were found, combined with Greek 'sauros' (lizard); meaning 'Niobrara lizard'.

89.8–83.6 million years ago Coniacian–Santonian, Late Cretaceous
Late Cretaceous stages

Niobrarasaurus is an extinct genus of nodosaurid ankylosaurian dinosaur which lived during the Late Cretaceous, around 87 to 82 million years ago. Its fossils were found in the Smoky Hill Chalk Member of the Niobrara Formation, in western Kansas, which would have been near the middle of the Western Interior Seaway during the Late Cretaceous. It was probably closely related to Nodosaurus.

Diagnosis

  1. Armor on snout composed of two pairs of elongated scutes rather than one pair as in other nodosaurids
  2. Secondary palate extending caudally further than in other nodosaurids
  3. Caudal vertebral neural spines short and terminating in expanded knob, resembling Edmontonia
  4. Anterior caudal vertebral transverse processes projecting backwards rather than forwards
  5. Humerus with shallower olecranon notch between radial and ulnar condyles compared to similar nodosaurids
  6. Deltopectoral crest undifferentiated from humeral head by a step
  7. Fourth trochanter on femur with medial expansion approximately one-third down shaft
  8. Large triangular armor spines with hollow rather than solid base

Species

Niobrarasaurus coleii Carpenter et al., 1995

Type species

Named for Virgil Cole, the geologist who discovered and excavated the holotype specimen in 1930.

Holotype
FHSM VP-14855 , Sternberg Museum of Natural History, Fort Hays State University
Material
Fragmentary skeleton including skull parts, teeth, cervical/dorsal/caudal vertebrae, ribs, sacrum, ilia, scapulocoracoid, humerus, ulna, radius, metacarpals, femur, tibia, fibula, pes, and armor
Horizon
lower Smoky Hill Chalk Member, Niobrara Chalk Formation, Coniacian–Santonian, Late Cretaceous , 89.8–83.6 million years ago
Locality
tributary of Smoky Hill River, Kansas, United States

References

  1. Carpenter, K.; Dilkes, D.; Weishampel, D. B. (1995). The Dinosaurs of the Niobrara Chalk Formation (Upper Cretaceous, Kansas). Journal of Vertebrate Paleontology 15(2): 275-297. Informa UK Limited. doi:10.1080/02724634.1995.10011230 carpenter1995a
  2. Carpenter, K.; Everhart, M. J. (2007). Skull of the ankylosaur Niobrarasaurus coleii (Ankylosauria: Nodosauridae) from the Smoky Hill Chalk (Coniacian) of western Kansas. Transactions of the Kansas Academy of Science 110(1/2): 1-9. doi:10.1660/0022-8443(2007)110[1:sotanc]2.0.co;2

    Records the holotype's transfer from the University of Missouri to the Sternberg Museum, which is why it carries an FHSM number.

    carpenter2007b