Alisitos Fm. (UCB A-8331): Late/Upper Aptian, Mexico

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Anthozoa - Scleractinia - Montlivaltiidae
Montlivaltia sp. Lamouroux 1821
a category
Placosmilia sp. Milne-Edwards and Haime 1848
a category
Gastropoda - Liotiidae
Encycloscala emersoni n. sp. Allison 1955
c category
originally entered as "Encycloscala emersoni"
Gastropoda - Trochidae
Calliostoma (Calliostoma) aff. cragini (Stanton 1947)
f category
original and current combination Calliostoma cragini
(Calliostoma) - originally entered as "Calliostoma aff. cragini"
Gastropoda - Epitoniidae
Opalia (Crassiscala) riachuelanum (Maury 1936)
f category
Amaea (Confusiscala) sp. (de Boury 1909)
r category
original and current combination Confusiscala
Gastropoda - Metacerithiidae
Metacerithium sp. Cossmann 1906
f category
Gastropoda - Turritellidae
Mesalia (Mesalia) mauryae n. sp. Allison 1955
c category
? Turritella durhami n. sp. Allison 1955
f category
Turritella (Haustator) aff. seriatimgranulata (Roemer 1849)
a category
original and current combination Turritella seriatimgranulata
(Haustator) - originally entered as "Turritella aff. seriatimgranulata"
Gastropoda - Potamididae
Pyrazus (Echinobathra) durhami Allison 1955
f category
Gastropoda - Tylostomatidae
Tylostoma allisoni Squires and Saul 2004
Squires and Saul 2004 r category
Gastropoda - Aporrhaidae
Anchura (Anchura) andersoni n. sp. Allison 1955
c category
Gastropoda - Neogastropoda - Fasciolariidae
Euthriofusus wenzi n. sp. Allison 1955
c category
Gastropoda - Purpurinidae
Microschiza (Cloughtonia) scalaris (Conrad in Lynch 1852)
f category
Gastropoda - Naticidae
Natica japonica (Nagao 1934)
a category
original and current combination Vanikoro japonica
Gastropoda - Triforidae
Cerithiella (Cerithiella) ? kickapooense (Stanton 1947)
c category
(Cerithiella) - originally entered as "Cerithiella ? kickapooense"
Gastropoda - Cassiopidae
Cassiope (Gymnetome) gwynae n. sp. Allison 1955
a category
Cassiope (Cassiope) kleinpelli n. sp. Allison 1955
a category
Gastropoda - Heterostropha - Acteonellidae
Actaeonella fusiformis Coquand 1865
a category
Gastropoda - Heterostropha - Ringiculidae
? Oligoptycha popenoei n. sp. Allison 1955
r category
Gastropoda - Heterostropha - Tubiferidae
Pseudonerinea stantoni n. sp. Allison 1955
c category
Pseudonerinea stirtoni Allison 1955
a category
n. sp.
Gastropoda - Heterostropha - Nerinellidae
Aptyxiella (Endiatrachelus) parallela (Anderson and Hanna 1935)
c category
recombined as Nerinella parallela
Bivalvia - Cardiida - Veneridae
Resatrix sp. Casey 1952
c category
Bivalvia - Cardiida - Cardiidae
? Integricardium sp. Rollier 1912
f category
originally entered as "? Intergricardium sp."
Protocardia stonei
r category
Bivalvia - Trigoniida - Trigoniidae
Trigonia stolleyi Hill 1893
r category
Scaphopoda - Dentaliida - Dentaliidae
Dentalium sp. Linnaeus 1758
c category
see common names

Geography
Country:Mexico State/province:Baja California
Coordinates: 31.5° North, 116.7° West (view map)
Paleocoordinates:29.9° North, 68.2° West
Geographic resolution:small collection
Time
Period:Cretaceous Epoch:Early/Lower Cretaceous
Stage:Aptian 10 m.y. bin:Cretaceous 3
*International age/stage:Aptian - Albian
Key time interval:Late/Upper Aptian
Age range of interval:122.46000 - 112.03000 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Formation:Alisitos Member:lower
Stratigraphic resolution:bed
Stratigraphy comments: Age: "Aptian to middle Albian." Squires and Saul (2004) confirming and following Allison (1974) place this collection in the Late Aptian.
Lithology and environment
Primary lithology:volcaniclastic,brown,gray,green lithified siltstone
Lithology description: "Moderately well consolidated, massive, gray-green to brown tuffaceous siltstone...~10-15 m above lowest mid cret. exposures along south side of Punta China."
Environment:shallow subtidal indet.
Taphonomy
Modes of preservation:body
Collection methods and comments
Collection methods:mechanical,field collection
Reason for describing collection:taxonomic analysis
Taxonomic list comments: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."
Metadata
Database number:1890
Authorizer:J. Alroy, A. Hendy Enterer:M. Sommers, A. Hendy
Modifier:A. Hendy Research group:marine invertebrate
Created:1999-06-10 17:12:21 Last modified:2006-09-08 17:41:14
Access level:the public Released:1999-06-10 17:12:21
Creative Commons license:CC BY
Reference information

Primary reference:

51. 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]

Secondary references:

18606 R. L. Squires and L. R. Saul. 2004. Uncommon Cretaceous naticiform gastropods from the Pacific Slope of North America. The Velliger 47(1-2):21-37 [A. Miller/A. Hendy]