KT boundary Brazos 1 - A2.75 (Cretaceous of the United States)

Also known as Brazos River Section

Where: Texas (31.1° N, 96.8° W: paleocoordinates 34.5° N, 66.6° W)

• coordinate estimated from map

When: Corsicana Formation, Late/Upper Cretaceous (100.5 - 66.0 Ma)

Environment/lithology: deep subtidal shelf; claystone

• middle to outer shelf environment
• Brazos-1 comprises approx. 1m of Cretaceous clay with dark clay clasts (up to 10 cm in diameter) at the base (Unit A) with evidence of physical disruption

•also see Figure 3 for the detailed section; Units B-E probably form a tempestite or tsunami

Size classes: macrofossils, mesofossils

Collection methods: bulk

Primary reference: T. Hansen, R. B. Farrand, H. A. Montgomery, H. G. Billman, and G. Blechschmidt. 1987. Sedimentology and extinction patterns across the Cretaceous-Tertiary boundary interval in East Texas. Cretaceous Research 8:229-252 [B. Seuss/B. Seuss]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 225662: authorized by Barbara Seuss, entered by Barbara Seuss on 24.05.2022

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
unclassified
  -
Heterohilicidae indet., Micula mura, Margaritella sp.
Gastropoda
  -
Gastropoda indet.
Gastropoda indet. Cuvier 1795 snail
 Sorbeoconcha - Naticidae
Naticidae indet.
Naticidae indet. Guilding 1834 moon snail
Scaphopoda
 Dentaliida - Dentaliidae
Dentalium leve
Dentalium leve Stephenson 1923 tusk shell
Bivalvia
 Nuculanida - Nuculanidae
Nuculana coloradoensis, Nuculana travisana, Nuculana "sp. A", Nuculana "sp. B", Nuculana sp., Nuculana "sp. E", Nuculana protexta
Nuculana coloradoensis pointed nut clam
Nuculana travisana pointed nut clam
Nuculana "sp. A" Link 1807 pointed nut clam
Nuculana "sp. B" Link 1807 pointed nut clam
Nuculana sp. Link 1807 pointed nut clam
adult, juvenile
Nuculana "sp. E" Link 1807 pointed nut clam
Nuculana protexta pointed nut clam
 Arcida - Arcidae
Striarca webbervillensis
 Ostreida - Ostreidae
Ostrea "sp. A", Ostrea sp.
Ostrea "sp. A" Linnaeus 1758 oyster
Ostrea sp. Linnaeus 1758 oyster
 Ostreida - Flemingostreidae
"Ostrea tecticosta" = Cubitostrea tecticosta
"Ostrea tecticosta" = Cubitostrea tecticosta Gabb 1860 oyster
 Carditida - Carditidae
Vetericardiella webbervillensis
 Pholadida - Corbulidae
Corbula sp.
Corbula sp. Bruguière 1789 clam
 Cardiida - Mactridae
Cymbophora cancellosa
Cephalopoda
 Ammonitida - Scaphitidae
Scaphites sp.
Scaphites sp. Parkinson 1811 ammonite
 Ammonitida - Baculitidae
Baculites sp.
Baculites sp. Lamarck 1799 ammonite
Coccolithophyceae
 Braarudosphaerales - Polycyclolithaceae
Micula prinsii
Micula prinsii Perch-Nielsen 1979 coccolithophore
 Podorhabdales - Axopodorhabdaceae
Nephrolithus frequens
Foraminifera
 Globigerinaceae - Heterohelicidae
Heterohelix navarroensis, Heterohelix striata, Pseudoguembelina sp., Guembelitria cretacea
Heterohelix striata Ehrenberg 1840
Guembelitria cretacea Cushman 1933