KT boundary Brazos 1 - A4.00 (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 225661: 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
Foraminifera
  - Guembelitriidae
Guembelitria cretacea
Guembelitria cretacea Cushman 1933
 Globigerinaceae - Heterohelicidae
Pseudoguembelina sp., Heterohelix navarroensis, Heterohelix striata
Heterohelix navarroensis Loeblich 1951
Heterohelix striata Ehrenberg 1840
Coccolithophyceae
 Podorhabdales - Axopodorhabdaceae
Nephrolithus frequens
 Braarudosphaerales - Polycyclolithaceae
Micula prinsii
Micula prinsii Perch-Nielsen 1979 coccolithophore
Gastropoda
 Sorbeoconcha - Naticidae
Naticidae indet.
Naticidae indet. Guilding 1834 moon snail
 Neogastropoda - Fasciolariidae
Anomalofusus sp.
Anomalofusus sp. Wade 1916 snail
 Neogastropoda - Paladmetidae
Paladmete sp.
Paladmete sp. Gardner 1916 snail
Scaphopoda
 Dentaliida - Dentaliidae
Dentalium leve
Dentalium leve Stephenson 1923 tusk shell
Cephalopoda
 Ammonitida - Scaphitidae
Scaphites sp.
Scaphites sp. Parkinson 1811 ammonite
 Ammonitida - Baculitidae
Baculites sp.
Baculites sp. Lamarck 1799 ammonite
Bivalvia
 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, juvenila
 Solemyida - Solemyidae
Solemya sp.
Solemya sp. Children 1823 Awning Clam
 Cardiida - Mactridae
Cymbophora cancellosa
 Carditida - Crassatellidae
Crassatella sp.
Crassatella sp. Lamarck 1799 clam
 Arcida - Arcidae
Striarca webbervillensis, Arca sp.
Arca sp. Linnaeus 1758 ark
 Ostreida - Flemingostreidae
"Ostrea tecticosta" = Cubitostrea tecticosta
"Ostrea tecticosta" = Cubitostrea tecticosta Gabb 1860 oyster
 Ostreida - Ostreidae
Ostrea "sp. A", Ostrea sp.
Ostrea "sp. A" Linnaeus 1758 oyster
Ostrea sp. Linnaeus 1758 oyster