Quebrada Cucuruchu (Miocene of Venezuela)

Where: Venezuela (11.5° N, 69.5° W: paleocoordinates 11.2° N, 67.9° W)

• coordinate stated in text

When: El Muaco Member (Caujarao Formation), Tortonian (11.6 - 7.2 Ma)

• Kavanagh de Petzall (1959) divided the Caujarao Formation into three members: El Muaco (lower), Mataruca (middle) and Taratara (upper), where the latter one is underlying La Vela Formation (Miocene–Pliocene). The fossiliferous localities here studied belong to the El Muaco Member (Fig. 2), which is 690 m thick and with a lithology characterized mainly by mudstones and clays with some limestones and sandstones well developed at the basal section of the member (Kavanagh de Petzall 1959; Vallenilla 1961).

Environment/lithology: estuary or bay; gray mudstone

• The mixture of marine and freshwater/terrestrial fauna observed in these fossiliferous layers of the Quebrada Cucuruchu and Puerto Chavez localities, which includes amber fragments (Fig. 5a–d) and carbonized vegetation, could be inferred as the result of the input of streams and rivers from the backshore to the littoral marine environment, evidence of mixed coastal marine and fluvial–estuarine environments. The presence of freshwater and continental faunal (e.g., terrestrial sloths and pampatherids) surrounding the littoral area where the Muaco Member was deposited could suggest the presence of rivers with savanna and forest areas.
• The fossiliferous locality in Quebrada Cucuruchu corresponds to a dark-gray mudstone layer of 50 cm with abundant molluscan, ichnofossils and vertebrates remains, which underlay a hard coquinoid layer.

Size classes: macrofossils, mesofossils

Collection methods: surface (in situ), mechanical, ,

• The specimens were extracted from the sediment/rocks mechanically, and these are housed in the paleontological collection of the Museo Angel Segundo Lopez, Taratara, Falcon State, Venezuela, with the acronym MTT-V.

Primary reference: J. D. Carrillo-Briceno, A. E. Reyes-Cespedes, R. Salas-Gismondi and R. Sanchez. 2018. A new vertebrate continental assemblage from the Tortonian of Venezuela. Swiss Journal of Palaeontology 1-12 [E. Vlachos/E. Vlachos]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 200110: authorized by Evangelos Vlachos, entered by Evangelos Vlachos on 14.03.2019

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Chondrichthyes
 Odontaspidida - Jaekelotodontidae
Anotodus sp. Le Hon 1871 elasmobranch
 Myliobatiformes - Dasyatidae
Dasyatidae indet. Jordan 1888 whiptail stingray
 Myliobatiformes - Myliobatidae
Aetomylaeus sp. Garman 1908 eagle ray
 Lamniformes - Otodontidae
"Carcharocles megalodon" = Otodus megalodon
"Carcharocles megalodon" = Otodus megalodon Agassiz 1843 megalodon
 Carchariniformes - Carcharhinidae
Negaprion sp. Whitley 1940 lemon shark
Galeocerdo aduncus Agassiz 1843 tiger shark
Carcharhinus leucas Valenciennes 1839 requiem shark
 Carchariniformes - Sphyrnidae
Sphyrna mokarran hammerhead shark
 Carchariniformes - Hemigaleidae
"Hemipristis serra" = Hemipristis heteropleurus
"Hemipristis serra" = Hemipristis heteropleurus Agassiz 1844 ground shark
Actinopteri
 Acanthomorphata - Sphyraenidae
Sphyraena sp. Walbaum 1792 barracuda
 Acanthomorphata - Lutjanidae
 Tetraodontiformes - Diodontidae
 Tetraodontiformes - Balistidae
Balistes sp. Linnaeus 1758
 Siluriformes - Pimelodidae
Pimelodidae indet. Eigenmann and Eigenmann 1918 catfish
 Characiformes - Serrasalmidae
Serrasalmidae indet. Günther 1864
Reptilia
 Testudines - Panchelidae
Chelus sp. Duméril 1806 sideneck turtle
One of the fragments (MTT-V-80, Fig. 3r) corresponds to a carapace fragment preserving the posterior costals 6–8, while the other fragment (MTT-V-80A, Fig. 3s) corresponds to the posterior plastral lobe (xiphiplastra), where portions (most posterior regions) of both hypoplastra are preserved too
 Pseudosuchia - Gavialidae
Gavialidae indet. Adams 1854 archosaur
Mammalia
 Xenarthra - Pampatheriidae
Scirrotherium sp. Edmund and Theodor 1997 edentate