El Rosario: Late/Upper Turonian - Early/Lower Coniacian, Mexico

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Heterohelicidae
Heterohelix sp. Ehrenberg 1843
Marginotruncanidae
Whiteinella sp. Pessagno 1967
Globotruncanidae
Dicarinella sp. Porthault 1970
Marginotruncana sp.
unclassified
Plantae indet. Haeckel 1866
Fossil wood
Actinopteri - Pycnodontiformes
Pycnodontiformes indet. Berg 1937
Actinopteri - Salmoniformes
? Cimolichthyoidei indet. Goody 1969
Actinopteri - Salmoniformes - Prionolepididae
? Prionolepididae indet. Goody 1969
Actinopteri - Aulopiformes
? Enchodontoidei indet. Berg 1937
Actinopteri
Acanthomorpha indet. (Rosen 1973)
spelled with current rank as Acanthomorphata
Actinopteri - Tselfatiiformes
Tselfatiiformes indet. Nelson 1994
Actinopteri - Ichthyodectiformes
Ichthyodectiformes indet. Bardack and Sprinkle 1969
Reptilia
cf. Muzquizopteryx sp. Frey et al. 2006
Frey et al. 2012 1 specimen
MUDE CPC-484, right wing skeleton
Nyctosauridae indet. (Hay 1902)
1 individual
New genus and species, "Chango"
    = Muzquizopteryx coahuilensis n. gen., n. sp. Frey et al. 2006
Frey et al. 2006
UNAM IGM 8621, near complete skeleton with soft tissues
Crocodylia indet. (Owen 1842)
1 element
PAS 629, vertebra
? Varanoidea indet. Gray 1827
2 elements
MHM PAS 337, centrum; 338A, B
    = Platynota indet. Baur 1890
Reynoso and Cruz 2014
Reptilia - Mosasauridae
Mosasauridae indet. Gervais 1852
1 specimen
MHM PAS 336, partial tail
Chondrichthyes
Elasmobranchii indet. (Bonaparte 1838)
Chondrichthyes - Lamniformes - Mitsukurinidae
cf. Scapanorhynchus sp. Woodward 1889
Chondrichthyes - Hybodontiformes - Ptychodontidae
Ptychodus cf. mortoni Mantell 1836
Bivalvia - Myalinida - Inoceramidae
Mytiloides herbichi
Restricted to the "grey member"
Mytiloides scupini
Restricted to the "grey member"
Mytiloides incertus (Jimbo 1894)
Restricted to the "grey member"
Cremnoceramus waltersdorfensis
Subspecies: waltersdorfensis. Occurs higher in the section.
Cremnoceramus crassus
Subspecies: inconstans. Occurs higher in the section.
Cremnoceramus deformis (Meek 1871)
Subspecies: deformis and erectus. Occurs higher in the section.
Bivalvia - Ostreida - Posidoniidae
Didymotis costatus
Restricted to the "grey member"
Cephalopoda - Ammonitida - Tetragonitidae
Gaudryceras mite (Hauer 1866)
Cephalopoda - Ammonitida - Collignoniceratidae
Peroniceras tridorsatum (Schlüter 1867)
Forresteria brancoi
Forresteria alluaudi (Boule et al. 1907)
recombined as Forresteria (Forresteria) alluaudi
Cephalopoda - Ammonitida - Scaphitidae
Scaphites frontierensis
Scaphites uintensis
Scaphites preventricosus Cobban 1951
Scaphites sagensis Cobban 1952
synonym of Scaphites (Scaphites) meslei
Cephalopoda - Ammonitida - Diplomoceratidae
? Neocrioceras sp.
Cephalopoda - Ammonitida - Baculitidae
Baculites yokoyamai (Tokunga and Shimizu 1926)
Malacostraca - Decapoda - Ctenochelidae
cf. Callianassa sp. Leach 1814
    = Gourretia aquilae Rathbun 1935
Vega et al. 2007
Malacostraca - Decapoda - Cenomanocarcinidae
Brachyura indet. (Latreille 1802)
New family
    = Cenomanocarcinus vanstraeleni Stenzel 1945
Vega et al. 2007
see common names

Geography
Country:Mexico State/province:Coahuila
Coordinates: 28.9° North, 102.4° West (view map)
Paleocoordinates:31.0° North, 71.2° West
Basis of coordinate:stated in text
Altitude:1350 meters
Geographic resolution:outcrop
Time
Period:Cretaceous Epoch:Late/Upper Cretaceous
10 m.y. bin:Cretaceous 6
Key time interval:Late/Upper Turonian - Early/Lower Coniacian
Age range of interval:93.90000 - 86.30000 m.y. ago
Stratigraphy
Geological group:Austin
Stratigraphic resolution:formation
Stratigraphy comments: Limestone in the quarry has been divided into three members (basal gray, middle yellow, upper white); pterosaur-bearing layer is of early Coniacian age
Lithology and environment
Primary lithology:concretionary,pyritic lime mudstone
Secondary lithology: marl
Lithology description: "The sediments are best described by the German word Plattenkalk. The lithology corresponds to micritic, evenly layered, platy limestone, mostly with internal millimetric bedding (flinze), and intercalated calcareous, fine-layered marls (Fäulen)"..."The sediment sequence is monotoneous and consists of evenly layered platy limestone and interlayered millmetrically-layered marls. The limestone layers are micritic mudstones, wackestones, and packstones, with shell hash. Dismicrite or microsparite only occur occasionally as the result of diagenetic overprint. This limestine is between a few tens of mm and more than 0.5 m thick, massive or millimetrically laminated, and resistant to weathering. Carbonate content of the limestone is always higher than 95%. The interlayered marl units reach thickness of 1 m or more."
Environment:offshore shelf
Geology comments: "Quiet water marine environment. Stagnation and a hostile oxygen-deficient bottom environment are indicated by the near-absence of trace fossil and benthic invertebrate associations...Anoxoic conditions are also indicated by thin laminae to thick horizons with concretions of goethite, which formed from the oxidation of primary pyrite, and by the early diagenetic phosphatization of vertebrate and invertebrate fossils...Low energy currents occurred only occasionally and probablyvery locally...Deposition occurred below storm wave base...The abundance of ammonoids, inoceramids and planktonic foraminifera indicate a water depth of at least 50 m, an open marine shelf environment, and normal stenohaline confitions. The extremely rare shallow water, terrestrial and semi-aquatic organisms, and drift wood suggest a distant coast line (>100 km)."
Taphonomy
Modes of preservation:body,mold/impression,trace,soft parts,recrystallized,original calcite,replaced with calcite,replaced with pyrite,replaced with phosphate
Lagerst�tten type:conservation
Size of fossils:macrofossils,mesofossils,microfossils
Spatial orientation:random
Preservation of anatomical detail:excellent
Abundance in sediment:abundant
Articulated whole bodies:many
Associated major elements:many
Disassociated major elements:many
Disassociated minor elements:many
Fragmentation:occasional
Temporal resolution:snapshot
Spatial resolution:parautochthonous
Collection methods and comments
Reason for describing collection:general faunal/floral analysis
Taxonomic list comments:Stramentum barnacle actually from Carranza, according to Ifrim et al., 2011
Metadata
Database number:92293
Authorizer:R. Butler, M. Clapham, M. Carrano Enterer:R. Butler, M. Clapham, M. Carrano
Modifier:M. Carrano Research group:marine invertebrate,taphonomy,vertebrate
Created:2009-11-05 05:12:10 Last modified:2022-07-01 12:15:09
Access level:the public Released:2009-11-05 05:12:10
Creative Commons license:CC BY
Reference information

Primary reference:
31102. W. Stinnesbeck, C. Ifrim, H. Schmidt, A. Rindfleisch, M.-C. Buchy, E. Frey, A. H. González-González, F. J. Vega, L. Cavin, G. Keller, and K. T. Smith. 2005. A new lithographic limestone deposit in the Upper Cretaceous Austin Group at El Rosario, county of Múzquiz, Coahuila, northeastern Mexico. Revista Mexicana de Ciencias Geológicas 22:401-418 [R. Butler/R. Butler]

Secondary references:

31103 E. Frey, M.-C. Buchy, W. Stinnesbeck, A. González González, and A. Stefano. 2006. Muzquizopteryx coahuilensis n. g., n. sp., a nyctosaurid pterosaur with soft tissue preservation from the Coniacian (Late Cretaceous) of northeast Mexico (Coahuila). Oryctos 6:19-39 [R. Butler/R. Butler]
43463 E. Frey, R. A. Elgin, W. Stinnesbeck, J. M. Padilla-Gutierrez, C. Ifrim, S. Giersch, and A. H. Gonzalez-Gonzalez. 2012. A new specimen of nyctosaurid pterosaur, cf. Muzquizopteryx sp. from the Late Cretaceous of northeast Mexico. Revista Mexican de Ciencais Geologicas 29:131-139 [R. Butler/R. Butler]
82054 E. Frey and W. Stinnesbeck. 2014. Mexican pterosaurs—rare jewels in the fossil record. In H. E. Rivera-Sylva, K. Carpenter, & E. Frey (eds.), Dinosaurs and Other Reptiles from the Mesozoic of Mexico 126-142 [M. Carrano/M. Carrano]
82053 V. H. Reynoso and J. A. Cruz. 2014. Mesozoic lepidosauromorphs of Mexico: a review and discussion of taxonomic assignments. In H. E. Rivera-Sylva, K. Carpenter, & E. Frey (eds.), Dinosaurs and Other Reptiles from the Mesozoic of Mexico 44-78 [M. Carrano/M. Carrano]
43158decapod F. J. Vega, T. Nyborg, A. Rojas-Briceno, P. Patarroyo, J. Luque, H. Porras-Muzquiz, and W. Stinnesbeck. 2007. Upper Cretaceous Crustacea from Mexico and Colombia: similar faunas and environments during Turonian times. Revista Mexicana de Ciencias Geologicas 24(3):403-422 [C. Schweitzer/E. Johnson/M. Uhen]