''Silvisaurus'', from the Latin silva "woodland" and Greek sauros "lizard", is a

nodosaurid Nodosauridae is a family of ankylosaurian dinosaurs, from the Late Jurassic to the Late Cretaceous period in what is now North America, South America, Europe, and Asia. Description Nodosaurids, like their close relatives the ankylosaurids, we ...

ankylosaur from the

Early Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early ...

to Late Cretaceous period.

Discovery and species

A fossil of the species was discovered in the fifties by rancher Warren H. Condray of Wells, KS. He notified senator

Frank Carlson Frank Carlson (January 23, 1893May 30, 1987) was an American politician who served as the 30th governor of Kansas, Kansas State representative, United States representative, and United States senator from Kansas. Carlson is the only Kansan to ...

who directed him to the chancellor of the University of Kansas,

Franklin David Murphy Franklin David Murphy (January 29, 1916 – June 16, 1994) was an American administrator, educator, and medical doctor. During his life, he served as Chancellor of the University of Kansas (KU) and Chancellor of the University of California, Los ...

. Murphy sent the preparator of the paleontology of vertebrates department of the natural history museum of the university, Russell R. Camp, to investigate the matter. In July 1955 Camp, with help from Condray, recovered the skeleton of a dinosaur. It was further prepared by Camp and Glenn H. Marihugh. In 1961 the find was described and named by Theodore H. Eaton jr., also from the University of Kansas, as the type species ''Silvisaurus condrayi''. The generic name is derived from Latin ''silva'', "wood", in reference to the probably densely forested habitat of the animal. The specific name honours Condray.Eaton, T.H., Jr. 1960.
A new armored dinosaur from the Cretaceous of Kansas
. ''The University of Kansas Paleontological Contributions: Vertebrata'' 8: 1-24. To date, ''Silvisaurus'' includes only the type species. The holotype, KU 10296, was found in exposures of the Terracota Clay Member of the Dakota Formation (late

Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...

-early Cenomanian) in Kansas, and consists of an incomplete skeleton with skull. It includes the mandible, eight neck vertebrae, ten dorsal vertebrae, a sacrum of six sacral vertebrae, three tail vertebrae, a left pubis fragment, the lower end of the right femur, and a toe phalanx. Additionally disarticulated plates and spikes from the body armour were discovered. The condition of the fossil was poor as the bones had been exposed at the bottom of a dry riverbed and had been weathered and trampled by cattle. Some elements were only present as impressions or natural casts.

Paleobiology

Based on the remains, the animal is estimated to have been approximately in length. Its skull measures in length and is wide. The bony secondary palate is poorly developed in ''Silvisaurus'', the

dentary In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

includes at least twenty-five teeth, the basal tubera of the

basioccipital The basilar part of the occipital bone (also basioccipital) extends forward and upward from the foramen magnum, and presents in front an area more or less quadrilateral in outline. In the young skull this area is rough and uneven, and is joined t ...

are bulbous, and each

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has ...

holds eight to nine teeth. The presence of teeth at the front of the jaw suggests that this may have been a relatively primitive nodosaur, since most later forms had a toothless beak instead. In addition to the usual rounded and polygonal

osteoderm Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amp ...

s, ''Silvisaurus'' may have also sported bony spines on its shoulders and tail. The head contained large air passages, which may have been used for loud vocalisations, presumably for communication.

Classification

This taxon represents a relatively primitive nodosaurid, and Vickaryous ''et al.'' (2004) have stated that "''

Sauropelta ''Sauropelta'' ( ; meaning 'lizard shield') is a genus of nodosaurid dinosaur that existed in the Early Cretaceous Period of North America. One species (''S. edwardsorum'') has been named although others may have existed. Anatomically, ''Saurope ...

edwardsorum'', ''Silvisaurus condrayi'', and '' Pawpawsaurus campbelli'' form a basal polytomy nested deep to '' Cedarpelta''."

References

*Vickaryous, Maryanska, and Weishampel 2004. Chapter Seventeen: Ankylosauria. in The Dinosauria (2nd edition), Weishampel, D. B., Dodson, P., and Osmólska, H., editors. University of California Press. {{Taxonbar, from=Q133169 Nodosaurids Late Cretaceous dinosaurs of North America Fossil taxa described in 1960 Paleontology in Kansas Ornithischian genera

Discovery and species

Paleobiology

Classification

See also

References