Santa Rosa (LACM Loc. 6289) (Oligocene of Peru)

Also known as Yurua River

Where: Departamento de Ucayali, Peru (9.5° S, 72.8° W: paleocoordinates 11.5° S, 66.2° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Yahuarango Formation, Rupelian (33.9 - 28.1 Ma)

• Either latest Eocene or earliest Oligocene (Seiffert et al. 2020).

•Campbell et al. (2021). The Santa Rosa fossil locality in eastern Perú produced the first Paleogene vertebrate fauna from the Amazon Basin, including the oldest known monkeys from South America. This diverse paleofauna was originally assigned an Eocene age based largely on the stage of evolution of the site’s caviomorph rodents and marsupials. Here, we present detrital zircon dates that indicate that the maximum composite age of Santa Rosa is 29.6 ± 0.08 Ma (Lower Oligocene), although several zircons from Santa Rosa date to the Upper Oligocene. The first appearance datum for Caviomorpha in South America is purported to be the CTA-27 site in the Contamana region of Perú, which is hypothesized to be ∼41 Ma (Middle Eocene) in age. However, the presence of the same caviomorph species and/or genera at both CTA-27 and at Santa Rosa is now difficult to reconcile with a >11-My age difference. To further test the Middle Eocene age estimate for CTA-27, we ran multiple Bayesian tip-dating analyses of Caviomorpha, treating the ages of all Paleogene species from Perú as unknown. These analyses produced mean age estimates for Santa Rosa that closely approximate the maximum 29.6 ± 0.08 Ma composite date provided by detrital zircons, but predict that CTA-27 is much younger than currently thought (∼30 Ma). We conclude that the ∼41 Ma age proposed for CTA-27 is incorrect, and that there are currently no compelling Eocene records of either rodents or primates in the known fossil record of South America.

• group of beds-level stratigraphic resolution

Environment/lithology: terrestrial; lithified, massive, muddy mudstone and unlithified, fine-grained, sandy sandstone

• Moderately indurated massive clays and mudstones, with occasional bedding visible. Thin horizons a few centimeters thick of unconsolidated, variously colored fine sand of mixed composition are frequently encountered. Also frequently encountered are calcareous and hematitic conglomeratic lenses, the latter appearing to replace the former.

Size classes: macrofossils, mesofossils

Preservation: original phosphate, bone collector

Collected by Kenneth E. Campbell, Carl D. Frailey, Lidia Romero-Pittman, and Manuel Aldana in 1995; reposited in the FMNH, LACM, MLP

Collection methods: sieve,

• The most of collected individuals was in Museum of Los Angeles

•County (LACM), California, USA

Primary reference: K. E. Campbell, C. D. Frailey, and L. Romero-Pittman. 2004. The Paleogene Santa Rosa Local Fauna of Amazonian Perú: Geographic and Geologic Setting. Natural History Museum of Los Angeles County, Science Series 40:3-14 [J. Zijlstra/J. Zijlstra/P. Mannion]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 149523: authorized by Carlos Jaramillo, entered by Andrés Cárdenas on 07.08.2013, edited by Richard Butler, Philip Mannion and Kateryn Pino

Creative Commons license: CC BY (attribution)

Taxonomic list

Mammalia
 Tribosphenida - Jaskhadelphyidae
Kiruwamaq chisu n. gen. n. sp.7
Kiruwamaq chisu n. gen. n. sp.7 Goin and Candela 2004 metatherian
LACM 140619, an almost complete, isolated left M?3.
 Polydolopimorphia -
Wamradolops tsullodon n. gen. n. sp.7
Wamradolops tsullodon n. gen. n. sp.7 Goin and Candela 2004 metatherian
HOLOTYPE. LACM 140590, a right maxilla fragment with complete P3–M2 (Fig. 6). HYPODIGM. The holotype; LACM 140584, right horizontal ramus with M1–3 and alveoli of M4 (Fig. 8); LACM 140640, isolated left P3; LACM 140601, isolated left ?dp3; LACM 140654, isolated right M1 (Figs. 9A–C); LACM 140645, isolated right M1; LACM 140657, isolated left M1; LACM 140660, isolated left M1; LACM 140656, isolated right M1 (Figs. 9D–F); LACM 140672, isolated fragmentary right M2; LACM 140655, isolated right M2; LACM 140658, isolated right M2 (Figs. 9G–I); LACM 140609, isolated right M2; LACM Goin and Candela: Paleogene Marsupials 140659, isolated left M2; LACM 140648, isolated M2; LACM 140588, isolated left M3; LACM 140626, isolated left M3 (Figs. 7B–C); LACM 140587, isolated left M3; LACM 140586, isolated right M3; LACM 140589, isolated left M3; LACM 140608, isolated left M4; LACM 140594, isolated right P2; LACM 140595, isolated left P2; LACM 140591, partial left maxilla with P3–M1; LACM 140597, isolated right M1, very worn; LACM 140616, fragment of an isolated right M1, without the anterior portion; LACM 144510, isolated left M1; LACM 140593, isolated right M1 (Fig. 7A); LACM 140585, isolated right M2 (Figs. 7D–E); LACM 140596, isolated right M3; LACM 140592, isolated left M3 (Figs. 7F–G); LACM 140625, iso- lated left M4; LACM 144512, isolated left M4.
 Polydolopimorphia - Rosendolopidae
Hondonadia pittmanae n. sp.7 Goin and Candela 2004 metatherian
HOLOTYPE. LACM 140615, an isolated, broken left Mx. HYPODIGM. The holotype and LACM 144516, a partial ?left Mx.
 Polydolopimorphia - Prepidolopidae
Incadolops ucayali n. gen. n. sp.7
Incadolops ucayali n. gen. n. sp.7 Goin and Candela 2004 metatherian
LACM 144513, isolated left Mx.
 Sparassodonta -
Patene campbelli n. sp.7 Goin and Candela 2004 metatherian
LACM 140628, isolated left M4.
 Tribosphenida - Herpetotheriidae
Rumiodon sp.7, Rumiodon inti n. gen. n. sp.7
Rumiodon sp.7 Goin and Candela 2004 marsupial
LACM 140583, left mandibular fragment with almost complete M3–4, and LACM 144518, isolated left trigonid.
Rumiodon inti n. gen. n. sp.7 Goin and Candela 2004 marsupial
HOLOTYPE. LACM 144515, isolated right M1. HYPODIGM. The holotype; LACM 140661, isolated right M?2; and LACM 140687, isolated left lower premolar.
 Microbiotheria - Microbiotheriidae
Kirutherium paititiensis n. gen. n. sp.7
Kirutherium paititiensis n. gen. n. sp.7 Goin and Candela 2004 marsupial
LACM 140620, an isolated left M3, broken at its labial third.
 Paucituberculata - Caenolestidae
Perulestes fraileyi n. gen. n. sp.7, Perulestes cardichi n. gen. n. sp.7
Perulestes fraileyi n. gen. n. sp.7 Goin and Candela 2004 marsupial
HOLOTYPE. LACM 140651, an incomplete right M4, without its anterior half and part of the stylar shelf (Fig. 13). HYPODIGM. The holotype; LACM 140622, right M1 without talonid (Fig. 14A); LACM 140600, right M1 without the talonid; LACM 140653, right M?1 without the trigonid (Fig. 14B); LACM 144511, isolated left M3; and LACM 144514, isolated right M1.
Perulestes cardichi n. gen. n. sp.7 Goin and Candela 2004 marsupial
HOLOTYPE. LACM 140649, a complete, iso- lated right M1 (Figs. 11A–B). HYPODIGM. The holotype; LACM 140606, al- most complete, isolated left M2 (Fig. 12); LACM 140604, almost complete, isolated right M2; LACM 140652, isolated right M2 with talonid bro- ken; LACM 149364, isolated left M2; LACM 140603, isolated right trigonid of M3; LACM 140605, isolated left M3; LACM 140599, isolated right talonid of M4; LACM 140610, isolated left M?3, broken in its lingual half; LACM 140624, fragment of left M1 with only its parastylar corner; LACM 140650, isolated right M1, complete, but very worn; LACM 140686, fragment of left M2 with only parastylar corner; LACM 149363, iso- lated left M2; LACM 140703, isolated, very worn left M2; LACM 140613, complete, isolated right M4 (Figs. 11C–D); LACM 140618, partial right M4 with only posterior half; and LACM 140614, par- tial left M4 with only posterior half.
 Paucituberculata - Palaeothentidae
Sasawatsu mahaynaq n. gen. n. sp.7
Sasawatsu mahaynaq n. gen. n. sp.7 Goin and Candela 2004 marsupial
HOLOTYPE. LACM 140668, a complete, iso- lated right M3 (Fig. 15A). HYPODIGM. The holotype; LACM 149366, isolated right M3; LACM 140695, distal portion of lower right incisor (I2); LACM 140607, fragment of horizontal ramus with intra-alveolar portion of hypertrophied incisor, M2 complete, and alveoli of P2–M1 and M3–4; LACM 140611, complete, isolat- Goin and Candela: Paleogene Marsupials ed left M2 (Fig. 16); LACM 140646, partial right M?2 without posterior half of talonid; LACM 144509, isolated right M4; LACM 140647, upper ?right molar (M?4), lingual half only (Fig. 15B). TENTATIVELY REFERRED SPECIMEN. LACM 149365, right M?2 (see ‘‘Comments’’).
 Chiroptera -
Chiroptera indet.5 Blumenbach 1779 bat
LACM 140623, left lower molar
 Notoungulata -
Toxodontia "C"10 Ameghino 1887 notoungulate
LACM 144305, right lower m?1
Toxodontia "B"10 Ameghino 1887 notoungulate
LACM 144304, upper premolar
Toxodontia "A"10 Ameghino 1887 notoungulate
LACM 140569, upper left M1 or M2
 Notoungulata - Notohippidae
cf. Notohippidae indet.10 Ameghino 1894 notoungulate
LACM 140570, lower m1 or m2
 Notoungulata - Interatheriidae
Interatheriinae indet.10 Simpson 1945 notoungulate
LACM 140571, partial left mandible with m1-3 (only trigonid of m3)
 Rodentia -
cf. Canaanimys maquiensis1 Antoine et al. 2011 caviomorph
LACM 159308 and more
Pozomys "sp. nov.?"1 Boivin et al. 2017 caviomorph
LACM 159408, 159411 and 159456
Pozomys ucayaliensis1 Boivin et al. 2017 caviomorph
LACM 143291 and more
cf. Pozomys ucayaliensis1 Boivin et al. 2017 caviomorph
LACM 159426
Vucetichimys pretrilophodontia n. gen. n. sp.2 Arnal et al. 2022 caviomorph
Holotype: CPI-9992 right M1 or M2; and Referred material: CPI-9978 right m1 or m2; LACM 159184 left M3; LACM 159186 left M1 or M2; LACM 159187 left m1 or m2; LACM 159189 left M3; LACM 159190 left M1 or M2; LACM 159192 left M1 or M2; LACM 159193 right M1 or M2; LACM 159272 left M1 or M2; LACM 159296 right M1 or M2; LACM 159406 right DP4; LACM 159471 right m1 or m2; LACM 159480 right m1 or m2; LACM 159482 right m1 or m2; LACM 159485 right m1 or m2; LACM 159486 right m1 or m2; LACM 159487 right m1 or m2; LACM 159488 left m1 or m2; LACM 159491 left m1 or m2; LACM 159492 left m3; LACM 159493 left m1 or m2; LACM 159495 right m1 or m2; LACM 159497 left m1 or m2; LACM 159498 right m3; LACM 159510 right m1
Ucayalimys amahuacencis n. sp.2 Arnal et al. 2022 caviomorph
Holotype: CPI-10014, left M1 and M2 (originally LACM 144299).
Balsayacuy huallagaensis2 Boivin et al. 2021 caviomorph
LACM 159208 left M1 or M2; LACM 159210 right M3; LACM 159284 left M1 or M2; LACM 159287 right M1 or M2; LACM 159370 left M1 or M2
Eobranisamys romeropittmanae n. gen. n. sp.6 Frailey and Campbell 2004 caviomorph
HOLOTYPE. LACM 144297, partial maxilla with right M1–2. REFERRED SPECIMENS. Maxilla, partial, right, with M2–M3, 144296; M3: left, 143354, 143381, 149490; right, 143364, 143365, 149493. Mx: left, 149482; right, 143355, 143356, 143357, 143358, 143359, 143360, 143362. Mandible, par- tial, right, with dp4–M2, 144293; left, with dam- aged dp4–M2, 144292. dp4: left, 143352, 143423 (partial); 143505 (partial); right, 143419. M1: left, 149487. M3: left, 143347. Mx: left, 143341, 143342, 143343, 143346, 149462; right, 143266, 143344, 143345, 149483.
Eobranisamys romeropittmanae2 Frailey and Campbell 2004 caviomorph
HOLOTYPE. LACM 143264, left Mx. REFERRED SPECIMENS. Mx: left, 143353, 149455; right, 149454, 149466, 149479.
Eobranisamys riverai n. sp.6 Frailey and Campbell 2004 caviomorph
HOLOTYPE. LACM 143503, right M1. REFERRED SPECIMENS. M2: right, 143378. M3: left, 143302; right, 143428. Mx: left, 143372, 143373, 143377, 149474; right, 149464. dp4: left, 143368 (partial), 143369, 143506; right, 143270 (partial), 143371. Mx: left, 143366, 143367, 149456, 149461, 149475; right, 149476, 149485.
 Rodentia - Agoutidae
Agoutidae "B"6 Gray 1821 caviomorph
LACM 143375, right upper Mx.
Agoutidae "C"6 Gray 1821 caviomorph
LACM 143349 and 143351, left lower Mx.
Agoutidae "A"6 Gray 1821 caviomorph
LACM 144299, right lower Mx.
Eoincamys ameghinoi n. sp.6 Frailey and Campbell 2004 caviomorph
HOLOTYPE. LACM 143339, left Mx. REFERRED SPECIMENS. Maxilla, partial, with P4–M2, 149495. P4: left, 149473; right, 149430. M3: left, 143315; right, 143340. Mx: left, 143320, 143338, 143396 (partial), 149470; right, 143279, 143437, 143468, 149450. P4: left, 143332; right, 143445. Mx: left, 143280, 143435, 149435, 149442; right, 143507, 149444.
Eoincamys pascuali n. gen. n. sp.6 Frailey and Campbell 2004 caviomorph
HOLOTYPE. LACM 143318, left Mx. REFERRED SPECIMENS. P4: left, 143321; right, 143313, 143322. M3: right, 143324. Mx: left, 143314, 143316, 143319, 149463; right, 143312, 143317, 143323, 149478. dp4 : left, 143335, 143456; right, 143328, 143331. P4: 143301, 143333, 143334, 143336. M1: left, 143303. M3: right, 149445, 149449. Mx: left, 143304, 143306, 143307, 143308, 143309, 149446; right, 143299, 143300, 143305, 143310, 143427, 143434, 143504, 149452, 149453.
 Rodentia -
Shapajamys minor n. sp.2 Arnal et al. 2022 caviomorph
Holotype: CPI-9980, left M1 and M2; and LACM 159478 right m1 or m2
 Rodentia - Erethizontidae
Eopululo wigmorei n. gen. n. sp.6
Eopululo wigmorei n. gen. n. sp.6 Frailey and Campbell 2004 porcupine
HOLOTYPE. LACM 143269, right upper Mx. REFERRED SPECIMENS. Upper Mx: left, 149489; right, 143272. Lower Mx: left, 143410, 149465; right, 143263 (partial), 143268 (partial).
 Rodentia -
Cachiyacuy kummeli1 Antoine et al. 2011 caviomorph
LACM 159244 and more
cf. Cachiyacuy kummeli1 Antoine et al. 2011 caviomorph
LACM 159523
cf. Cachiyacuy contamanensis1 Antoine et al. 2011 caviomorph
LACM 143376 and more
Eoespina woodi n. gen. n. sp.6 Frailey and Campbell 2004 caviomorph
HOLOTYPE. LACM 143286, left Mx. REFERRED SPECIMENS. P4: left, 144301; right, 143432, 143459, 149468. M2: left, 149441. M3: left, 143288, 143298; right, 143297. Mx: left, 143291, 143293, 143397, 144300, 149431, 149432, 149471, 149484; right, 143289, 143290, 143295, 143296, 143384, 143455, 143457, 149427, 149433, 149436, 149437. Mandibular fragment, right, with P4–M2, 144294. dp4: left, 149440; right, 143391, 143403, 143404 (partial), 143405, 143448 (partial). P4: left, 143283. M1: left, 149425, 149469; right, 149434. M3: left, 143386, 143438; right, 143282, 143440, 143461. Mx: left, 143389, 143436, 143446; right, 143281, 143327, 143330, 143385, 143390, 143439, 143447, 149429, 149486.
Eosachacui lavocati n. gen. n. sp.6 Frailey and Campbell 2004 caviomorph
HOLOTYPE. LACM 143294, left Mx. REFERRED SPECIMENS. P4: left, 143433, 143458, 143466. M3: left, 143401. Mx: left, 143292, 143337, 143383, 143399,143444, 143453; right, 143278, 143285, 143387, 143388, 143454, 149438, 149439. dp4 : left, 143326, 143400, 143449 (partial); right, 143379, 143402. P4: left, 143394. M1: left, 143329, 149426; right, 143274. M3: left, 143395. Mx: left, 143287, 143393, 143408, 143417, 143431, 143442 (par- tial), 143443 (partial), 149447; right, 143325, 143382, 143421, 149428.
Eosallamys paulacoutoi n. gen. n. sp.6 Frailey and Campbell 2004 caviomorph
HOLOTYPE. LACM 143422, maxilla, partial, right, with P4–M3. REFERRED SPECIMENS. P4: left, 149460; right 143415, 149480. M3: right, 143363. Mx: left, 149494; right, 143267, 144302. dp4: left, 143418 (partial), 143451, 149458 (partial); right, 143370, 143420, 143450. P4: 149492. M3: right, 143262. Mx: right, 143265, 143361 (partial), 144524.
Eosallamys simpsoni n. sp.6 Frailey and Campbell 2004 caviomorph
HOLOTYPE. LACM 143424, right Mx. REFERRED SPECIMENS. P4: left, 149451. M3: left, 143380; right, 149448. Mx: left, 143374, 143376, 143398, 149457, 149459, 149481, 149488; right, 143411, 143429, 143430, 143441 (partial), 149472, 149477. dp4: left, 143452; right, 143406 (partial), 143407 (partial), 143443 (par- tial), 149467 (partial). P4: left, 143311. M3: left, 143284. Mx: left, 143276, 143416 (partial); right, 143273, 143275, 143412, 143413, 143414, 149491.
Eodelphomys almeidacomposi n. gen. n. sp.6 Frailey and Campbell 2004 caviomorph
LACM 144298, mandibular fragment, right, with M3.
 Rodentia - Echimyidae
Echimyidae "C"6 Gray 1825 spiny rat
LACM 143277, left upper Mx.
Echimyidae "A"6 Gray 1825 spiny rat
LACM 143409, partial right upper Mx.
Echimyidae "B"6 Gray 1825 spiny rat
LACM 143348, left lower Mx.
 Rodentia -
Hystricognatha indet.6 rodent
Mostly incisors. LACM 143271, 143350, 143392, 143425, 143426, 143460, 143462, 143463, 143464, 143465, 143467, and many unnumbered, fragmentary specimens of upper and lower teeth.
 Primates -
Perupithecus ucayaliensis n. gen. n. sp.3
Perupithecus ucayaliensis n. gen. n. sp.3 Bond et al. 2015 monkey
Complete upper left molar (M?1), Instituto Geolo ́gico, Minero y Metalu ́ rgico (INGEMMET), Lima, Colleccio ́ n Paleontolo ́ gica del INGEMMET (CPI) 6486. Natural History Museum of Los Angeles County (LACM) 6289/155085; plastotype.
 Primates - Parapithecidae
Ucayalipithecus perdita n. gen. n. sp.9
Ucayalipithecus perdita n. gen. n. sp.9 Seiffert et al. 2020 monkey
INGEMMET CPI 7936; hypodigm: CPI-7937 [LACM6289/155061], CPI-7938 [LACM 6289/157063] and CPI-7928
 Primates -
? Platyrrhini "A"3 monkey
Two additional primate upper molars, a left and right M1 or M2 (CPI-7000 and CPI-7001, respectively; LACM 6289/157193 and 6289/ 157063, casts)
? Platyrrhini "B"3 monkey
Isolated right M3 (CPI-6487; LACM 6289/156981, cast)
 Cingulata -
Yuruatherium tropicalis n. gen. n. sp.4
Yuruatherium tropicalis n. gen. n. sp.4 Ciancio et al. 2012 edentate
LACM 150606 (holotype), LACM 150604, LACM 150607, LACM 150610, LACM 150611.
 Cingulata - Dasypodidae
? Parastegosimpsonia sp.4 Ciancio et al. 2012 armadillo
LACM 150609, partial movable osteoderm.
Parastegosimpsonia peruana n. gen. n. sp.4 Ciancio et al. 2012 armadillo
LACM 150608.
 Marsupialia -
Wirunodon chanku n. gen. n. sp.7
Wirunodon chanku n. gen. n. sp.7 Goin and Candela 2004 marsupial
HOLOTYPE. LACM 140621, an isolated upper left M?3 (Fig. 18). HYPODIGM. The holotype and LACM 140677, an isolated right trigonid (Fig. 19).
 Allotheria -
? Gondwanatheria indet.8 Mones 1987 mammal
LACM 149371, isolated upper molariform lacking its roots. Identity uncertain, but "we regard the Gondwanatheria, and especially the Ferugliotheriidae, as our best estimate as to its possible allocation"