Meriden, Hypsognathus (Triassic of the United States)

Where: New Haven County, Connecticut (41.5° N, 72.8° W: paleocoordinates 20.6° N, 19.2° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: New Haven Formation (Chatham Group), Rhaetian (208.5 - 201.3 Ma)

• "The original provenance of the block containing YPM 55831 is unknown, but heavy-mineral analysis (Griggs, 1973) and the coarseness of the sandstone matrix indicate its derivation from the upper part of the New Haven Formation (formerly New Haven Arkose). This formation in the Hartford basin of the Newark Supergroup ranges in age from the Norian to the Hettangian. Its upper portion can be correlated with the upper part of the Passaic Formation of the Newark basin in New Jersey". Sues et al. (2000:fig. 1) show the specimen as coming from the Rhaetian part of the formation.

•Originally enterd group name >>Newark<< is replaced by >>Chatham<< since all Upper Triassic formations of the Newark Supergroup are assigned to the Chatham Group, according to Weems & Olsen (1997, GSA Bulletin 109(2)) (TL).

• bed-level stratigraphic resolution

Environment/lithology: terrestrial; lithified, coarse-grained sandstone

Size class: macrofossils

Preservation: mold/impression

Collected by D. Bazzano & R. Baron; reposited in the YPM

• David Bazzano & Robert Baron

Primary reference: H.-D. Sues, P. E. Olsen, D. M. Scott and P. S. Spencer. 2000. Cranial osteology of Hypsognathus fenneri, a latest Triassic procolophonid reptile from the Newark Supergroup of Eastern North America. Journal of Vertebrate Paleontology 20(2):275-284 [J. Mueller/J. Dummasch/R. Butler]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 89140: authorized by Richard Butler, entered by Richard Butler on 06.05.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

 Procolophonia - Procolophonidae
Hypsognathus fenneri Gilmore 1928 parareptile
YPM 55831, partial skeleton including skull and mandible