Where: Chiapas, Mexico (16.6° N, 92.9° W: paleocoordinates 18.4° N, 83.6° W)
• coordinate estimated from map
• outcrop-level geographic resolution
When: San Juan Formation, Lutetian (47.8 - 41.3 Ma)
• STRATIGRAPHIC RELATIONS: Assigned to the San Juan Formation in Vega et al. 2001, but reassigned to the El Bosque Formation by Perrilliat et al. (2006) on age, but not lithology. Formations are defined lithologically, not chronologically, so even if the early Eocene age is correct, it still belongs to the San Juan Formation. THICKNESS: From individual bed within section of 40 m thickness. Thickness of formation in this region is 200 m, but ranges from between 720 and 2000 m. AGE: 2). Presence of the foraminiferans Lepidocyclina (Polylepidina) antillea, Storrsella haastersi, Sigmoilopsis centralamericana, Nummulites (Paleonummulites) panamensis, and Pellatispirella matleyi suggest a middle Eocene age for the sediments of this locality. Later assigned to Ypresian on the basis of Sr isotope dating of nautilid Hercoglossa, which yields an age of ~52 Ma. The foraminiferal and lithostratigraphic context suggests the original middle Eocene age is more likely. STRATIGRAPHIC POSITION: From near top of section, within "Grit Mbr" (apparently informal) of the lower El Bosque Fm.
• bed-level stratigraphic resolution
Environment/lithology: open shallow subtidal; lithified, shelly/skeletal, yellow limestone
Size class: macrofossils
Preservation: cast, mold/impression
Collection methods: COLLECTOR: Not stated, but possibly including M. C. Perilliat and colleagures. REPOSITORY: Instituto de Geologia, UNAM, Ciudad Universitaria, Mexico (IGM).
Primary reference: M. D. Perrilliat, J. Avendano, F. J. Vega and J. Solé. 2006. Lower Eocene Gastropods from El Bosque Formation, Central Chiapas, Mexico. The Veliger 48(3):151-169 [A. Hendy/A. Hendy/M. Uhen]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 79943: authorized by Austin Hendy, entered by Austin Hendy on 27.03.2008, edited by Pete Wagner
Creative Commons license: CC BY (attribution)
Taxonomic list
Gastropoda | |
Tornatellaea bella Conrad 1860 snail | |
Architectonica sp. Röding 1798 sundial
Architectonica alabamensis Dall 1892 sundial | |
"Calyptraea aperta" = Calyptraea (Trochita) aperta
"Calyptraea aperta" = Calyptraea (Trochita) aperta Solander 1766 slipper shell | |
Pachycrommium clarki Stewart 1927 snail | |
Terebelum (Seraphs) sp. Montfort 1810 snail | |
Exilia sp. Conrad 1860 snail | |
Lapparia cf. nuda, Volutilithes cf. muricinus, Lyrischapa spinifera, Athleta petrosa, Volutocorbis minutus
Lapparia cf. nuda Stenzel and Turner 1940 volute
Volutilithes cf. muricinus Lamarck 1802 volute
Lyrischapa spinifera Perrilliat et al. 2006 volute
Volutocorbis minutus Perrilliat et al. 2006 volute | |
Turricula sp. Schumacher 1817 snail | |
? Cornulina sp. Conrad 1853 snail
Levifusus sp. Conrad 1865 snail | |
Sulcobuccinum cf. scalina Heilprin 1880 snail | |
Galeodea koureos Gardner 1939 snail | |
Bernaya (Bernaya) obesa, Bernaya (Bernaya) media, "Bernaya (Protocypraea) cf. angystoma" = Lyncina amygdalina, Macrocypraea veintensis n. sp., Proadusta sp., "Proadusta acyensis" = Eopustularia acyensis, "Proadusta subrostrata" = Eopustularia subrostrata, Cypraeorbis sp., Cypraeorbis alabamensis
Bernaya (Bernaya) obesa Deshayes 1866 cowry
"Bernaya (Protocypraea) cf. angystoma" = Lyncina amygdalina Deshayes 1835 cowry
Macrocypraea veintensis n. sp. Perrilliat et al. 2003 cowry
Proadusta sp. Sacco 1894 cowry
"Proadusta acyensis" = Eopustularia acyensis Raincourt 1876 cowry
"Proadusta subrostrata" = Eopustularia subrostrata Gray 1824 cowry Proadusta subrostrata bartonensis
Cypraeorbis sp. Conrad 1865 cowry
Cypraeorbis alabamensis de Gregorio 1890 cowry Cypraeorbis alabamensis ventripotens; Cypraeorbis alabamensis mexicana
| |
Eocypraea (Eocypraea) sp., Eocypraea (Eocypraea) cf. castacensis, "Eocypraea (Eocypraea) inflata" = Eocypraea inflata
Eocypraea (Eocypraea) sp. Cossmann 1903 snail
Eocypraea (Eocypraea) cf. castacensis Stewart 1927 snail
"Eocypraea (Eocypraea) inflata" = Eocypraea inflata Lamarck 1802 snail | |
Crommium globosa Perrilliat et al. 2006 moon snail | |
Cirsotrema sp. Mörch 1852 wentletrap | |
Mesalia alabamiensis, ? Palmerella sp., "Palmerella mortoni" = Kapalmerella mortoni, "Turritella" sp., "Turritella" humerosa
Mesalia alabamiensis De Gregorio 1890 turret shell
? Palmerella sp. Allmon 1996 turret shell
"Palmerella mortoni" = Kapalmerella mortoni Conrad 1830 turret shell SUBSPECIES: Palmerella mortoni mexicana
"Turritella" sp. Lamarck 1799 turret shell | |
Potamides (Potamidopsis) tricarinatus Lamarck 1804 horn snail | |
"Cerithium" sp. Bruguière 1789 cerith snail
"? Iddingsia sp." = Iddingsella Olsson 1944 cerith snail
Bittium (Bittium) estellense cerith snail originally Bittium (Bittium) estellensis, Palmer and Brann updated to Bittium (Bittium) estellense
| |
Trochus sp. Linnaeus 1758 top snail
Calliostoma granulata Perrilliat et al. 2006 top snail | |
Cephalopoda | |
Hercoglossa cf. ulrichi White 1882 nautiloid |