PBDB Collection

TAR-31 (Miocene of Peru)

Also known as Juan Guerra, Tarapoto

Where: San Martin, Peru (6.6° S, 76.3° W: paleocoordinates 7.2° S, 73.5° W)

• coordinate stated in text

When: Laventan mammal zone, Ipururo Formation, Serravallian (13.8 - 11.6 Ma)

• Boivin et al. (2021): These levels were originally mapped as belonging to the lower member of Ipururo Formation (middle Miocene in age in the Huallaga basin) [Antoine et al. 2021], an assignation in agreement with the nature of their facies and depositional environment sequence. The fossil content of the TAR-31 encompasses plants, amber clasts, crabs, chondrichthyans, osteichthyans, anurans, chelonians, crocodylomorphs, birds, and mammals (including metatherians, xenarthrans, liptoterns, notungulates, sirenians, chiropterans, primates, and caviomorph rodents). The TAR-31 mammal assemblage includes a didelphid marsupial (currently under study by one of us, NSS), the interatheriine notoungulate Miocochilius sp., the didolodontid Megadolodus sp., the platyrrhine primate Neosaimiri aff. fieldsi [Marivaux et al. 2020], and the caviomorph fauna described here (see ‘Age of TAR-31’ section of this present work). This assemblage recalls some of the Laventan SALMA localities: Quebrada Honda in Bolivia (13.112.2 Ma) [Gibert et al. 2020], the Fitzcarrald local fauna in SE Peru [Tejada-Lara et al. 2015], and especially the lower part of the Villavieja Formation in the La Venta area in Colombia (13.8–11.6 Ma; [Flynn et al. 1007] and see above). Accordingly, the TAR-31 locality most likely documents the late middle Miocene Laventan SALMA [Marivaux et al. 2020].

Environment/lithology: terrestrial; lithology not reported

• Boivin et al. (2021): TAR-31 consists of a 10–15 cm-thick yellow microconglomerate interbedded within a grey cross-stratified and sandstone-dominated fluvial unit (Fig 2A [Marivaux et al. 2020]). The latter is intercalated between thick violin-grey variegated paleosols pointing to the existence of a meandering river with a sustainable floodplain [Marivaux et al. 2020].

Size class: macrofossils

Collection methods: Boivin et al. (2021): The material from TAR-31 was collected by excavating and wet screening (2 and 1mm meshes) about 550 kg of sediment during our yearly field expeditions (August 2015, 2016, and 2018).

Primary reference: M. Boivin, L. Marivaux, W. Aguirre-Diaz, A. Benites-Palomino, G. Billet, F. Pujos, R. Salas-Gismondi, N. S. Stutz, J. V. Tejada-Lara, R. M. Varas-Malca, A. H. Walton and P.-O. Antoine. 2021. Late middle Miocene caviomorph rodents from Tarapoto, Peruvian Amazonia. PLoS ONE 16(11):e0258455 [J. Carrillo/K. Pino/P. Mannion]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 230802: authorized by Juan Carrillo, entered by Kateryn Pino on 21.07.2023

Creative Commons license: CC BY (attribution)

Taxonomic list

• Boivin et al. (2021): The primary purpose of the present work is to describe the new caviomorph materials found in TAR-31. The caviomorph material corresponds to about 400 isolated teeth (complete or fragmentary), one fragment of mandible (MUSM 4643), one fragment of maxilla (MUSM 4375), and one astragalus (MUSM 4658). No permits were required for the described study, which complied with all relevant regulations. The field work on TAR-31 was carried out in the framework of the ongoing cooperation agreement between the ‘Museo de Historia Natural de la Universidad Nacional Mayor San Marcos’ (Lima, Peru) and the ‘Institut des Sciences de l’Evolution de Montpellier-Universite ́ de Montpellier’ (France). The TAR-31 fossil specimens are permanently stored in the palaeontological collection of the ‘Museo de Historia Natural, Universidad Nacional Mayor de San Marcos’, Lima, Peru (MUSM).

Show authors, comments, and common names

Mammalia
Notoungulata - Interatheriidae	Miocochilius sp.¹ Miocochilius sp.¹ Stirton 1953 notoungulate
Primates - Cebidae	Neosaimiri cf. fieldsi¹ Neosaimiri cf. fieldsi¹ Stirton 1951 squirrel monkey MUSM-3888, right M3; MUSM-3890, left dP2; MUSM-3891, lingual part of a fragmentary right M1 or M2; MUSM-3892, MUSM-3893; MUSM-3894; MUSM-3895 right dC1
Rodentia -	Erethizontoidea indet., Nuyuyomys chinqaska n. sp. Erethizontoidea indet. Bonaparte 1845 caviomorph MUSM 4367, left p4 Nuyuyomys chinqaska n. sp. Boivin et al. 2021 caviomorph Holotype: MUSM 4308, right M1?
Rodentia - Caviidae	Caviidae indet. Caviidae indet. Gray 1821 caviomorph MUSM 4283, right p4
Rodentia -	Microscleromys sp., Microscleromys paradoxalis, Microscleromys cribriphilus Microscleromys sp. Walton 1990 caviomorph MUSM 4658, left astragalus Microscleromys paradoxalis Walton 1990 caviomorph MUSM 4643, left fragment of mandible bearing incisor and dp4–m1; ING-KU 8604, right fragment of mandible bearing p4–m2; MUSM 4640–4642, left dp4s; IGM 250306, left p4; IGM 250305 and 250308, right p4s; MUSM 4644, left lower molar; IGM 250265, MUSM 4645, right lower molar; IGM 250288, 250307, IGM-DU 88–814, 89–675, MUSM 4646–4650, left m1 or m2; IGM 250319, MUSM 4651–4656, right m1 or m2s; IGM 250274, 250285, 250304, MUSM 4657, left m3s; IGM 251020, right m3; IGM 250302, IGM-DU 88–815, ING-KU unnumbered specimen, MUSM 4623, left dP4s; MUSM 4624, left P4; MUSM 4625, right P4; MUSM 4626, left upper molar; MUSM 4627, right upper molar; IGM 250283, IGM-DU 89–673, MUSM 4628–4631, left M1 or M2?s; MUSM 4632–4636, right M1 or M2?s; IGM 250284, MUSM 4637, left M3?s; IGM-DU 85–410, MUSM 4638, 4639, right M3?s. Microscleromys cribriphilus Walton 1990 caviomorph MUSM 4545, right fragmentary dp4 or p4; MUSM 4532–4541, left dp4s; MUSM 4542–4544, right dp4s; IGM-DU 88–818, MUSM 4546–4550, left p4s; IGM 251018, MUSM 4551–4558, right p4s; IGM-DU 89676, left m1 or m2 (or p4); MUSM 4558–4561, left lower molars; MUSM 4562–4565, right lower molars; MUSM 4566, left m1 or m2?; IGM 250309, right m1 or m2?; MUSM 4567–4588, left m1?s; MUSM 4589–4600, right m1?s; MUSM 4601–4608, left m2?s; IGM 250303, MUSM 4609–4615, right m2s; MUSM 4621, left m3?; MUSM 4616–4620, left m3s; MUSM 4622, right m3; MUSM 4420–4433, left dP4s; IGM 250320, MUSM 4434–4447, right dP4s; MUSM 4469, right P4 or M3?; MUSM 4448–4458, left P4s; IGM 251040, MUSM 4459–4468, right P4s; MUSM 4470, 4471, left upper molars; MUSM 4472–4478, right upper molars; MUSM 44794497, left M1 or M2?s; MUSM 4498–4510, right M1 or M2?s; MUSM 4511–4513, left M2?s; MUSM 4514–4516, right M2?s; MUSM 4517–4524, left M3?s; MUSM 4525–4531, right M3?s.
Rodentia - Dinomyidae	Scleromys ? sp. Scleromys ? sp. Ameghino 1887 caviomorph MUSM 4277, left dp4; MUSM 4278, 4279, right fragmentary dp4s; MUSM 4280, left p4; MUSM 4281, 4282, right lower molars; MUSM 4270–4272, left fragmentary upper molars; MUSM 4273, 4274, left upper molars; MUSM 4275, 4276 right upper molars
Rodentia -	Octodontoidea indet. Octodontoidea indet. Waterhouse 1839 caviomorph MUSM 4662, left m1 or m2; MUSM 4660, left dP4; MUSM 4661, right M3.
Rodentia - Echimyidae	Ricardomys longidens Ricardomys longidens Walton 1990 spiny rat MUSM 4397–4401, left dp4s; MUSM 4402–4406, right dp4s; MUSM 4407, right lower molar; MUSM 4408, left m1 or m2?; MUSM 4409, left m1?; MUSM 4410, right m1?; MUSM 4411–4413, left m2?s; MUSM 4414, 4415, right m2?s; MUSM 4416–4419 , left m3?s; MUSM 4370–4373, 43914394, left upper teeth; MUSM 4374, 4395, 4396 right upper teeth; MUSM 4375, left fragment of maxillary bearing dP4 (or M1)? and M1 (or M2)?; MUSM4376, 4377, left dP4s (or M1s)?; MUSM 4378–4380, right dP4s (or M1s)?; MUSM 4381, right dP4?; MUSM 4382–4384, left M1 or M2?s; MUSM 43854388, right M1 or M2?s; MUSM 4389, left M2?; MUSM 4390, right M3?.
Panameriungulata - Proterotheriidae	Megadolodus sp.¹ Megadolodus sp.¹ McKenna 1956 placental
Didelphimorphia - Didelphidae	Thylamys cf. colombianus² Thylamys cf. colombianus² Goin 1997 fat-tailed mouse opossum MUSM 4018, left m1
Paucituberculata - Palaeothentidae	Palaeothentes sp.² Palaeothentes sp.² Ameghino 1887 marsupial MUSM 4019, left M1, MUSM 4020, left broken ?M2, MUSM 4021, right broken m1
Paucituberculata - Abderitidae	Pitheculites ipururensis n. sp.² Pitheculites ipururensis n. sp.² Stutz et al. 2022 marsupial Holotype: MUSM 4024, right m2, MUSM 4023, left broken m1, MUSM 4022, right broken m1

¹Marivaux et al. 2020; ²Stutz et al. 2022