Tio Gregorio (Miocene of Venezuela)

Also known as Urumaco

Where: Falcon, Venezuela (11.2° N, 70.3° W: paleocoordinates 11.0° N, 68.9° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Upper Member (Urumaco Formation), Late/Upper Miocene (11.6 - 5.3 Ma)

• The geological units from which the specimens were obtained are the middle and upper members of the Urumaco Formation of Venezuela. These units have been recently summarized in the Léxico estratigráfico de Venezuela (1997).

• member-level stratigraphic resolution

Environment/lithology: fluvial-deltaic; brown, gray claystone

• The paleoenvironments were tropical near shore marine to low coastal savannas with freshwater rivers.
• The upper member of the Urumaco Formation also comprises gray to brown often limey claystone with thin intercalated and locally conchiferous sandstones. The uppermost layer is referred to as the “capa de tortugas” because of its abundant remains of the turtle Bairdemys Gaffney & Wood. Several localities and levels have concentra- tions of vertebrate fossils. The vertebrate fauna includes marine, estuarine and freshwater fishes, terrestrial, freshwater and marine turtles and crocodilians, and terrestrial and aquatic/semiaquatic mammals (Sánchez-Villagra et al., 2003).

Size class: macrofossils

Primary reference: J. G. Lundberg and O. A. Aguilera. 2003. The late Miocene Phractocephalus catfish (Siluriformes: Pimelodidae) from Urumaco, Venezuela: additional specimens and reinterpretation as a distinct species. Neotropical Ichthyology 1(2):97-109 [C. Jaramillo/G. Ballen]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 136776: authorized by Carlos Jaramillo, entered by Gustavo Ballen on 04.12.2012, edited by Philip Mannion, Juan Carrillo and Evangelos Vlachos

Creative Commons license: CC BY (attribution)

Taxonomic list

Actinopteri
 Siluriformes - Pimelodidae
Phractocephalus nassi Lundberg and Aguilera 2003 cajaro
UNEFM-PF-0365 (paratype); UNEFM-PF-0366 (non-type); MCC-URU-2002-141, UNEFM-PF-0159 (non-types)
Reptilia
 Testudines - Podocnemidae
Bairdemys sanchezi n. sp.2 Gaffney et al. 2008 sideneck turtle
AMU-CURS 186, Skull, jaws, and anterior plastral fragment
 Crocodylia - Alligatoridae
Caimaninae indet.6 Brochu 1999 crocodilian
AMU-CURS-105 (cranium) and AMU-CURS-106 (mandible)
Purussaurus mirandai1 Aguilera et al. 2006 crocodilian
MCC URU-157-72V (dentary), AMU-CURS-33 (isolated posterior tooth)
Purussaurus cf. mirandai6 Aguilera et al. 2006 crocodilian
AMU-CURS-57 (mandible)
Mourasuchus sp.5 Price 1964 crocodilian
AMU-CURS-073 (right mandible and incomplete rostrum and postcranial material) and AMU-CURS-695
 Crocodylia -
Ikanogavialis gameroi n. gen. n. sp.7 Sill 1970 crocodilian
UCV-VF-1165 & 1166 - holotype (cranium and mandible); referred material: MCN-URU-2002-143 (cranium and mandible)
Gryposuchus croizati3 Riff and Aguilera 2008 crocodilian
AMU-CURS-58 (isolated skull)
Mammalia
 Rodentia - Neoepiblemidae
Phoberomys pattersoni4 Bondesio and Bocquentin Villanueva 1988 caviomorph
UNEFM-VF-020. Body mass estimates of 741Kg using the Femur.