| Silvisaurus Temporal range: Early-Late Cretaceous, 114–98 Ma |
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| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Superorder: | Dinosauria |
| Order: | †Ornithischia |
| Suborder: | †Ankylosauria |
| Family: | †Nodosauridae |
| Genus: | †Silvisaurus Eaton, 1960 |
| Species: | †S. condrayi |
| Binomial name | |
| Silvisaurus condrayi Eaton, 1960 |
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Silvisaurus, from the Latin silva "woodland" and Greek saurus "lizard", is a nodosaurid ankylosaur from the middle Cretaceous of Kansas.
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The holotype was discovered in 1955 by Warren Condray of Wells, KS, and recovered by T. H. Eaton from the University of Kansas from exposures of the Dakota Formation (late Aptian-early Cenomanian) in Kansas, and consists of an incomplete skeleton with skull and sacrum. To date, Silvisaurus includes only the type species, S. condrayi.
Based on these remains, the animal is estimated to have been approximately 4 metres (13 ft) in length. Its skull measures 33 centimetres (13 in) in length and is 25 centimetres (9.8 in) wide. The bony secondary palate is poorly developed in Silvisaurus, the dentary includes at least twenty-five teeth, the basal tubera of the basiocciptial are bulbous, and each premaxilla 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 osteoderms, 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.[1]
This taxon represents a relatively primitive nodosaurid, and Vickaryous et al. (2004) have stated that "Sauropelta edwardsorum, Silvisaurus condrayi, and Pawpawsaurus campbelli form a basal polytomy nested deep to Cedarpelta."