Alisitos Fm. (UCB A-8317): Late/Upper Aptian, Mexico

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Orbitolinidae
Orbitolina texana
c category
Nodosariata - Vaginulinida - Vaginulinidae
Lenticulina cf. subalta
quest. ident. - originally entered as "Lenticulina cf. subalta"
Echinoidea - Echinoneoida - Conulidae
Pygopyrina sp. Pomel 1883
c category
Gastropoda
? Pyrazus harrissi n. sp. Allison 1955
r category
recombined as Alamirifica harrissi
originally entered as "? Pyzarus harrissi"
Gastropoda - Potamididae
Pyrazus (Echinobathra) austinense (Roemer 1888)
f category
Pyrazus (Echinobathra) durhami n. sp. Allison 1955
r category
Gastropoda - Turritellidae
Omalaxis ? planorbis (Blainville 1827)
r category
originally entered as "Omalaxis ? planorbis"
Gastropoda - Naticidae
Natica importuna Nagao 1934
f category
Gastropoda - Aporrhaidae
Anchura (Perissoptera) hannai Allison 1955
quest. ident.
Gastropoda - Tylostomatidae
Tylostoma (Tylostoma) mutabilis (Gabb 1869)
c category
    = Tylostoma allisoni Squires and Saul 2004
Squires and Saul 2004
Gastropoda - Procerithiidae
Cimolithium eleanorae Allison 1955
c category
Cimolithium miyakoense (Nagao 1934)
c category
var. tomasensis n. var.
Uchauxia kirki Allison 1955
c category
Uchauxia beali Allison 1955
c category
Gastropoda - Heterostropha - Nerineidae
Nerinea (Plesioptygmatis) tomasensis Allison 1955
f category
Nerinea (Plesioptygmatis) cf. pseudoconvexa (Stanton 1947)
f category
(Plesioptygmatis) - originally entered as "Nerinea cf. pseudoconvexa"
Nerinea (Plesioptygmatis) bosei Allison 1955
f category
Gastropoda - Heterostropha - Nerinellidae
Aptyxiella (Aptyxiella) cf. subula (Roemer 1888)
f category
(Aptyxiella) - originally entered as "Aptyxiella cf. subula"
Gastropoda - Heterostropha - Acteonellidae
Actaeonella parvus (Stanton 1947)
f category
originally entered as "Acteonella parvus"
Gastropoda - Heterostropha - Acteonidae
Liocarenus (Liocarenus) formosum (Cragin 1893)
r category
Gastropoda - Trochidae
Tectus (Tectus) tomasensis n. sp. Allison 1955
r category
Gastropoda - Colloniidae
Cirsochilus gilberti n. sp. Allison 1955
Gastropoda - Chilodontaidae
Agnathodonta brooksi n. sp. Allison 1955
r category
n. sp. - originally entered as "Agnathodonta brooksi"
Gastropoda - Neridomidae
Neritoma (Neridomus) delpeyae n. sp. Allison 1955
r category
Gastropoda - Neritidae
Otostoma (Lyosoma) japonica (Nagao 1934)
c category
Semineritina apparata (Cragin 1893)
f category
Corsania (Corsania) allisoni n. sp. Saul and Squires 1997
Saul and Squires 1997
Bivalvia - Pholadida - Corbulidae
Corbula sp. Bruguière 1789
r category
Bivalvia - Hippuritida - Caprinuloideidae
Caprinuloidea sp. Palmer 1928
c category
Bivalvia - Cardiida - Tellinidae
Linearia sp. (Conrad 1860)
r category
original and current combination Linearis
Bivalvia - Carditida - Crassatellidae
Ptychomya ? densicostata Nagao 1934
r category
originally entered as "Ptychomya ? densicostata"
Bivalvia - Pectinida - Neitheidae
Neithea aff. occidentalis Conrad 1855
r category
originally entered as "Neithea aff. occidentalis"
Bivalvia - Pectinida - Limidae
Lima (Mantellum) sp. (Röding 1798)
r category
(Mantellum)
Bivalvia - Ostreida - Gryphaeidae
Exogyra cf. quitmanensis (Cragin 1893)
f category
originally entered as "Exogyra cf. quitmanensis"
Gryphaea wardi Hill and Vaughan 1898
c category
Malacostraca - Decapoda
Decapoda indet. Latreille 1802
crab fragments
Anthozoa - Scleractinia - Montastraeidae
Montastrea sp. (Blainville 1830)
f category
    = "Montastrea" sp. Blainville 1830
Kiessling 2008
original and current combination Montastraea
Anthozoa - Scleractinia - Astrocoeniidae
Astrocoenia sp. Milne-Edwards and Haime 1848
r category
Anthozoa - Scleractinia - Montlivaltiidae
Isastrea whitneyi Wells 1932
c category
Anthozoa - Scleractinia - Eugyridae
Myriophyllia cf. cuyleri (Wells 1932)
c category
original and current combination Eugyra cuyleri
originally entered as "Myriophyllia cf. cuyleri"
Demospongiae - Clavulina - Clionaidae
Cliona sp.
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
10 m.y. bin:Cretaceous 2-3
*International age/stage:Aptian - Albian
Key time interval:Late/Upper Aptian
Age range of interval:119.50000 - 113.00000 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Formation:Alisitos Member:upper
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: conglomerate
Environment:shallow subtidal indet.
Geology comments: "Poorly sorted dark volcanic breccia overlying A-8318."
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:1878
Authorizer:J. Alroy, W. Kiessling, J. Marcot, A. Miller Enterer:M. Sommers, W. Kiessling, A. Hendy, J. Marcot
Modifier:A. Hendy Research group:marine invertebrate
Created:1999-06-10 15:04:36 Last modified:2006-09-08 17:28:02
Access level:the public Released:1999-06-10 15:04:36
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:

26431 W. Kiessling. 2008. New opinions on coral taxonomy. [W. Kiessling/W. Kiessling/W. Kiessling]
76939 L. R. Saul and R. L. Squires. 1997. New species of neritid gastropods from Cretaceous and Lower Cenozoic strata of the Pacific Slope of North America. The Veliger 40(2):131-147 [J. Marcot/J. Marcot]
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]