LACM Loc. 8060, Río Guatemala (Oligocene of Puerto Rico)

Where: Puerto Rico (18.3° N, 67.0° W: paleocoordinates 17.6° N, 66.0° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: San Sebastian Formation, Late/Upper Oligocene (28.4 - 23.0 Ma)

• basal San Sebastian Formation

•

•Ortega-Ariza et al. 2015: Results indicate ages of middle to late Oligocene for the San Sebastian Formation (ca. 29.78– 26.51 Ma)

• bed-level stratigraphic resolution

Environment/lithology: lagoonal; conglomerate

• This unit likely represented a shallow marine or brackish nearshore lagoon.
• The overall lithology of the San Sebastian Formation along this section consists of conglomerates and paleosols interbedded with marine mudstones and siltstones and occasional cross-bedded coarse sand units (Ve ́lez-Juarbe et al., 2007).

Size class: macrofossils

Reposited in the LACM

Primary reference: J. Velez-Juarbe, T. Martin, R. D. MacPhee and D. Ortega-Ariza. 2014. The earliest Caribbean rodents: Oligocene caviomorphs from Puerto Rico. Journal of Vertebrate Paleontology 34(1):157-163 [M. Uhen/S. Alam/M. Uhen]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 155752: authorized by Mark Uhen, entered by Mark Uhen on 29.04.2014, edited by Philip Mannion and Evangelos Vlachos

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Reptilia
 Testudines - Pelomedusidae
Pelomedusidae indet.
Pelomedusidae indet. Cope 1868 sideneck turtle
 Loricata -
Crocodylia indet.
Crocodylia indet. crocodilian
Mammalia
 Sirenia - Dugongidae
Priscosiren atlantica n. gen. n. sp.3
Priscosiren atlantica n. gen. n. sp.3 Velez-Juarbe and Domning 2014 dugong
 Rodentia -
Caviomorpha indet., Borikenomys praecursor n. gen. n. sp.1, Caribeomys merzeraudi n. gen. n. sp.2
Caviomorpha indet. Wood and Patterson 1955 caviomorph
LACM 162448
Borikenomys praecursor n. gen. n. sp.1 Marivaux et al. 2020 caviomorph
LACM 162447 - holotype; hypodigm: LACM162446 and MA 316
Caribeomys merzeraudi n. gen. n. sp.2 Marivaux et al. 2021 rodent
Holotype. LACM 162449, right lower molar (m1 or m2; Figs 2A, 4). Hypodigm. In addition to the holotype, LACM 162478, a right fourth lower deciduous premolar (dp4; Figs 2B, 3).
Chondrichthyes
 Orectolobiformes - Ginglymostomatidae
Ginglymostomatidae indet.
Ginglymostomatidae indet. Gill 1862 nurse shark
1Marivaux et al. 2020; 2Marivaux et al. 2021; 3Velez-Juarbe and Domning 2014