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
Cephalopoda | |
Hercoglossa cf. ulrichi White 1882 nautiloid | |
Gastropoda | |
Calliostoma granulata Perrilliat et al. 2006 top snail
Trochus sp. Linnaeus 1758 top snail | |
Cirsotrema sp. Mörch 1852 wentletrap | |
"Calyptraea aperta" = Calyptraea (Trochita) aperta
"Calyptraea aperta" = Calyptraea (Trochita) aperta Solander 1766 slipper shell | |
"? Iddingsia sp." = Iddingsella Olsson 1944 cerith snail
Bittium (Bittium) estellense cerith snail originally Bittium (Bittium) estellensis, Palmer and Brann updated to Bittium (Bittium) estellense
"Cerithium" sp. Bruguière 1789 cerith snail | |
Mesalia alabamiensis, "Palmerella mortoni" = Kapalmerella mortoni, ? Palmerella sp., "Turritella" sp., "Turritella" humerosa
Mesalia alabamiensis De Gregorio 1890 turret shell
"Palmerella mortoni" = Kapalmerella mortoni Conrad 1830 turret shell SUBSPECIES: Palmerella mortoni mexicana
? Palmerella sp. Allmon 1996 turret shell
"Turritella" sp. Lamarck 1799 turret shell | |
Potamides (Potamidopsis) tricarinatus Lamarck 1804 horn snail | |
Pachycrommium clarki Stewart 1927 snail | |
Terebelum (Seraphs) sp. Montfort 1810 snail | |
Levifusus sp. Conrad 1865 snail
? Cornulina sp. Conrad 1853 snail | |
Turricula sp. Schumacher 1817 snail | |
Sulcobuccinum cf. scalina Heilprin 1880 snail | |
Exilia sp. Conrad 1860 snail | |
Volutilithes cf. muricinus, Lapparia cf. nuda, Lyrischapa spinifera, Volutocorbis minutus, Athleta petrosa
Volutilithes cf. muricinus Lamarck 1802 volute
Lapparia cf. nuda Stenzel and Turner 1940 volute
Lyrischapa spinifera Perrilliat et al. 2006 volute
Volutocorbis minutus Perrilliat et al. 2006 volute | |
Galeodea koureos Gardner 1939 snail | |
"Eocypraea (Eocypraea) inflata" = Eocypraea inflata, Eocypraea (Eocypraea) sp., Eocypraea (Eocypraea) cf. castacensis
"Eocypraea (Eocypraea) inflata" = Eocypraea inflata Lamarck 1802 snail
Eocypraea (Eocypraea) sp. Cossmann 1903 snail
Eocypraea (Eocypraea) cf. castacensis Stewart 1927 snail | |
Bernaya (Bernaya) media, Bernaya (Bernaya) obesa, Cypraeorbis sp., Cypraeorbis alabamensis, "Proadusta subrostrata" = Eopustularia subrostrata, "Proadusta acyensis" = Eopustularia acyensis, "Bernaya (Protocypraea) cf. angystoma" = Lyncina amygdalina, Macrocypraea veintensis n. sp., Proadusta sp.
Bernaya (Bernaya) obesa Deshayes 1866 cowry
Cypraeorbis sp. Conrad 1865 cowry
Cypraeorbis alabamensis de Gregorio 1890 cowry Cypraeorbis alabamensis ventripotens; Cypraeorbis alabamensis mexicana
"Proadusta subrostrata" = Eopustularia subrostrata Gray 1824 cowry Proadusta subrostrata bartonensis
"Proadusta acyensis" = Eopustularia acyensis Raincourt 1876 cowry
"Bernaya (Protocypraea) cf. angystoma" = Lyncina amygdalina Deshayes 1835 cowry
Macrocypraea veintensis n. sp. Perrilliat et al. 2003 cowry
Proadusta sp. Sacco 1894 cowry | |
Crommium globosa Perrilliat et al. 2006 moon snail | |
Tornatellaea bella Conrad 1860 snail | |
Architectonica sp. Röding 1798 sundial
Architectonica alabamensis Dall 1892 sundial |