Where: Kendall County, Texas (29.9° N, 98.8° W: paleocoordinates 27.9° N, 57.2° W)
When: Glen Rose Limestone Formation, Early/Lower Albian (112.0 - 109.0 Ma)
• The Glen Rose Limestone of Central Texas contains a scant ammonoid fauna
•which allows correlation with the European section (Young 1972:1 1, 1974:179). The Glen Rose Limestone is divided into upper and lower members by a bed (or zone of beds) containing numerous steinkems of the bivalve Corhula (Stricklin et al. 1971:23). The '"Corbula''' bed is used in this study as a stratigraphic marker to locate the stratigraphic position of each collection. All of the Glen Rose Limestone below the Corbula bed and to a level of about 41 m (135 ft) above it are considered to be Early Albian by Young (1974:176). This includes all of the specimens described in this study.
Environment/lithology: lagoonal or restricted shallow subtidal; burrowed limestone and marl
•weathering alternating with less resistant marls, giving rise to a characteristic stair-step topography (Fig. 1). The presence of mud cracks, bored bedding planes, bedding planes with encrusting oysters, algal mat laminations, ripple marks, dinosaur trailways, and plant debris is evidence for supratidal, intertidal. or shallow subtidal conditions. Beds of lime muds containing echinoids, miliolid foraminifera, infaunal pelecypods, corals and numerous gastropods imply marine conditions prevailed at times.
Size class: macrofossils
• The surface is covered by great numbers of fossils, especially the heart urchin Enallaster obliquatus. Other faunal elements include oysters, gastropods, and bivalves.
•The decapod part of the fauna from this locality is almost exclusively dominated
•by claws of the hermit crab, Pagurus banderensis. A collection of gastropod steinkerns was made to examine the possibility of preserved pagurids within the lithified mud of the steinkerns. No evidence of decapod exoskeleton was observed in the steinkerns. In fact, the steinkerns were packed with numerous shells and shell fragments mixed with carbonate mud. This suggests a fair amount of washing by currents or bioturbation after the shells were last occupied (by hermit crabs?) which would destroy evidence of any such occupation.
Preservation: cast, mold/impression, concretion
Primary reference: G.A. Bishop. 1983. Fossil decapod crustaceans from the Lower Cretaceous, Glen Rose Limestone of central Texas. Transactions of the San Diego Society of Natural History 20:27-55 [M. Clapham/J. Fearon]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 235834: authorized by Matthew Clapham, entered by J Fearon on 08.08.2024
Creative Commons license: CC BY (attribution)
Taxonomic list
•The decapod part of the fauna from this locality is almost exclusively dominated
•by claws of the hermit crab, Pagurus banderensis.
| unclassified | |
| Echinoidea | |
|
Enallaster obliquatus Clark 1893 heart urchin | |
| Malacostraca | |
|
| |
"Prehepatus hodgesi" = Necrocarcinus hodgesi
"Prehepatus hodgesi" = Necrocarcinus hodgesi Bishop 1983 crab | |
|
| |
| Bivalvia | |
|
Ostrea sp. Linnaeus 1758 oyster | |
| Gastropoda | |
|
Gastropoda sp. Cuvier 1795 snail | |