Alisitos Fm. (UCB A-8321) (Cretaceous of Mexico)

Where: Baja California, Mexico (31.5° N, 116.7° W)

• small collection-level geographic resolution

When: upper Member (Alisitos Formation), Late/Upper Aptian (122.5 - 113.0 Ma)

• Age: "Aptian to middle Albian." Squires and Saul (2004) confirming and following Allison (1974) place this collection in the Late Aptian.

• bed-level stratigraphic resolution

Environment/lithology: shallow subtidal; gray sandstone

• "Compact gray tuffaceous sandstone with large coral and molluscan fauna similar to A-8317. ~4 m strat above A-8323. On south side of point."

Collection methods: mechanical,

Primary reference: E. C. Allison. 1955. Middle Cretaceous gastropoda from Punta China, Baja California, Mexico. Journal of Paleontology 29(3):400-432 [J. Alroy/M. Sommers/J. Alroy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 1881: authorized by John Alroy, entered by Mike Sommers on 10.06.1999, edited by Austin Hendy and Wolfgang Kiessling

Creative Commons license: CC0 (CC0)

Taxonomic list

• Abundances: A = 20+, C = 6-20, F = 3-5, R = 1-2. "A spectacular feature of the middle Albian deposits at Punta China is the fine preservation exhibited by many of the fossils. Despite the coarseness of some of the volcanic breccias, fragile tests of Forams, echinoids, and small molluscs are almost perfectly preserved. Pelecypods almost always occur with both valves intact. Some gastropods retain original pigmentation."
Show authors, comments, and common names
Gastropoda
 Trochoidea - Trochidae
Tectus (Tectus) texanus, ? Tectus thalmanni n. sp.
Tectus (Tectus) texanus Roemer 1888 top snail
(Tectus)
? Tectus thalmanni n. sp. Allison 1955 top snail
 Trochoidea - Turbinidae
Angaria (Angaria) gwynae n. sp.
Angaria (Angaria) gwynae n. sp. Allison 1955 snail
 Sorbeoconcha - Naticidae
Natica importuna
Natica importuna Nagao 1934 moon snail
 Sorbeoconcha - Aporrhaidae
Anchura (Perissoptera) hannai n. sp.
Anchura (Perissoptera) hannai n. sp. Allison 1955 snail
 Sorbeoconcha - Cerithiopsidae
? Cerithiopsis stantoni n. sp.
? Cerithiopsis stantoni n. sp. Allison 1955 snail
 Sorbeoconcha - Procerithiidae
Cimolithium miyakoense, Cimolithium eleanorae n. sp., Uchauxia beali n. sp., Uchauxia kirki n. sp.
Cimolithium miyakoense Nagao 1934 snail
Cimolithium eleanorae n. sp. Allison 1955 snail
Uchauxia beali n. sp. Allison 1955 snail
Uchauxia kirki n. sp. Allison 1955 snail
 Sorbeoconcha - Tylostomatidae
Tylostoma allisoni n. sp.2
Tylostoma allisoni n. sp.2 snail
(Tylostoma) - originally entered as "Tylostoma cf. materinum"
 Cerithioidea - Cerithiidae
? Cerithium emersoni n. sp.
? Cerithium emersoni n. sp. Allison 1955 cerith snail
 Cerithioidea - Potamididae
Pyrazus (Echinobathra) durhami
Pyrazus (Echinobathra) durhami Allison 1955 horn snail
 Cerithioidea - Diastomatidae
Keilostoma quaidei n. sp.
Keilostoma quaidei n. sp. Allison 1955 snail
 Heterostropha - Nerinellidae
Aptyxiella (Aptyxiella) subula, "Aptyxiella (Endiatrachelus) parallela" = Nerinella parallela
"Aptyxiella (Endiatrachelus) parallela" = Nerinella parallela Anderson and Hanna 1935 snail
 Heterostropha - Nerineidae
Nerinea (Plesioptygmatis) bosei n. sp., "Nerinea cf. pseudoconvexa" = Nerinea (Plesioptygmatis) pseudoconvexa
Nerinea (Plesioptygmatis) bosei n. sp. Allison 1955 snail
"Nerinea cf. pseudoconvexa" = Nerinea (Plesioptygmatis) pseudoconvexa Stanton 1947 snail
originally entered as "Nerinea cf. pseudoconvexa"
Bivalvia
 Hippuritida - Caprinuloideidae
Caprinuloidea sp.
Caprinuloidea sp. Palmer 1928 rudist
Echinoidea
 Spatangoida - Toxasteridae
Enallaster ? texanus
Enallaster ? texanus Roemer 1849 heart urchin
originally entered as "Enallaster ? texanus"
Anthozoa
 Scleractinia - Montastraeidae
""Montastrea" sp." = Montastraea1
""Montastrea" sp." = Montastraea1 Blainville 1830 stony coral
 Scleractinia - Dermosmiliidae
Dermosmilia sp.
Dermosmilia sp. Koby 1884 stony coral
 Scleractinia - Astrocoeniidae
Astrocoenia sp.
Astrocoenia sp. Milne-Edwards and Haime 1848 stony coral
 Scleractinia - Cyathophoridae
Cyathophora sp.
Cyathophora sp. Michelin 1843 stony coral
1Kiessling 2008; 2Squires and Saul 2004