Also known as SMU 223

Where: Somervell County, Texas (35.4° N, 102.4° W: paleocoordinates 34.0° N, 59.0° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Lower Member (Glen Rose Limestone Formation), Early/Lower Albian (112.0 - 109.0 Ma)

• fossils are apparently from a single bed

•The Glen Rose formation spans through four ammonite zones with ages between latest Aptian and early Albian. Young 1974 suggested the Kasanskyella spathi ammonite zone is latest aptian, the Hypacanthoplites cragini zone is earliest Albian, the Douvilleiceras mammillatum and Hypacanthoplites comalensis zones are early Albian and may extend into the middle Albian. The Salenia texana Zone and Corbula bed fall within the mammillatum zone. The benthic foraminifera Orbitolina texana also suggests a late aptian - early albian age and is found in basal levels and in the upper member (Stricklin et al. 1971). Scott et al. (2007) estimated that the age of the Glen Rose Formation ranges from 113.3 to 108.0 Ma.

• bed-level stratigraphic resolution

Environment/lithology: deltaic; shale and mudstone

Size class: mesofossils

Primary reference: D. A. Winkler, P. A. Murry, and L. L. Jacobs. 1990. Early Cretaceous (Comanchean) vertebrates of central Texas. Journal of Vertebrate Paleontology 10(1):95-116 [J. Alroy/J. Alroy/J. Alroy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 27603: authorized by John Alroy, entered by John Alroy on 13.12.2002

Creative Commons license: CC BY (attribution)