KT boundary Brazos 1 - A0.75 (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 225668: 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
Coccolithophyceae
 Podorhabdales - Axopodorhabdaceae
Nephrolithus frequens
 Braarudosphaerales - Polycyclolithaceae
Micula prinsii
Micula prinsii Perch-Nielsen 1979 coccolithophore
unclassified
  -
Heterohilicidae indet., Vereticardiella webbervillensis, Cyclinchna incisa, Micula mura
Foraminifera
  - Guembelitriidae
Guembelitria cretacea
Guembelitria cretacea Cushman 1933
 Globigerinaceae - Heterohelicidae
Heterohelix glabra, Heterohelix striata, Heterohelix navarroensis, Pseudoguembelina sp.
Heterohelix striata Ehrenberg 1840
Heterohelix navarroensis Loeblich 1951
Bivalvia
  -
Bivalvia indet.
Bivalvia indet. Linnaeus 1758 clam
 Pectinida - Entoliidae
Syncyclonema simplicus
 Pectinida - Anomiidae
Anomia argentaria
Anomia argentaria Morton 1833 jingle
 Ostreida - Ostreidae
Ostrea "sp. A", Ostrea sp.
Ostrea "sp. A" Linnaeus 1758 oyster
Ostrea sp. Linnaeus 1758 oyster
 Arcida - Parallelodontidae
Nemodon lineatus
Nemodon lineatus clam
Nemodon eufalensis lineatus
 Arcida - Arcidae
Striarca webbervillensis
 Cardiida - Mactridae
Cymbophora cancellosa, Cymbophora sp.
Cymbophora sp. Gabb 1869 clam
 Nuculanida - Nuculanidae
Nuculana coloradoensis, Nuculana travisana, Nuculana "sp. A", Nuculana sp.
Nuculana coloradoensis pointed nut clam
Nuculana travisana pointed nut clam
Nuculana "sp. A" Link 1807 pointed nut clam
Nuculana sp. Link 1807 pointed nut clam
adult
Scaphopoda
 Dentaliida - Dentaliidae
Dentalium "sp. B", Dentalium leve
Dentalium "sp. B" Linnaeus 1758 tusk shell
Dentalium leve Stephenson 1923 tusk shell
Cephalopoda
 Ammonitida - Baculitidae
Baculites sp.
Baculites sp. Lamarck 1799 ammonite
Gastropoda
 Cerithioidea - Turritellidae
Turritella sp.
Turritella sp. Lamarck 1799 turret shell