Old Trail Museum locality L-6/Bob's Tuesday Site (Cretaceous of the United States)

Where: Teton County, Montana (47.8° N, 112.2° W: paleocoordinates 55.3° N, 77.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Lower Member (Two Medicine Formation), Campanian (83.6 - 72.1 Ma)

• lower part of formation, but slightly higher in section than main Seven Mile Hill exposures, which are underlain by a crystal tuff dated at 80.0 ± 0.1 Ma

• formation-level stratigraphic resolution

Environment/lithology: pond; burrowed, concretionary, green claystone and concretionary sandstone

• "sediments largely consisting of fluvial channel sandstones, green to gray overbank mudstones with common paleosol development, and ephemeral floodplain pond deposits...All tyrannosaurid and hadrosaur bones lie horizontally within a 20 cm thick block, green claystone with occasional calcitic nodules and vertical to subvertical burrows...deposition took place in quiet ephemeral waters such as in a floodplain pond. Below the bone-bearing unit lies a green claystone distinguished only by an increased number of molluscs and shell debris. Overlying the bone-bearing unit, sediments gradually coarsen over a 10-15 cm interval to a very fine sandstone with more common calcitic nodules "

Size classes: macrofossils, mesofossils

Preservation: soft parts

Collection methods: quarrying, mechanical,

Primary reference: D. J. Varricchio. 2001. Gut contents from a Cretaceous tyrannosaurid: implications for theropod dinosaur digestive tracts. Journal of Paleontology 75(2):401-406 [M. Carrano/M. Carrano/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 36608: authorized by Matthew Carrano, entered by Matthew Carrano on 06.02.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
  -
Bivalvia indet. Linnaeus 1758 clam
Gastropoda
 Basommatophora - Physidae
Physa sp. Draparnaud 1801 pulmonate
Reptilia
 Avetheropoda - Tyrannosauridae
Daspletosaurus sp. Russell 1970 tyrannosaurine
 Avetheropoda - Dromaeosauridae
Saurornitholestes sp. Sues 1978 coelurosaur
teeth
 Neornithischia - Hadrosauridae
Hadrosauridae indet. Cope 1869 hadrosaurid
some as gut contents of tyrannosaurid