Punta Peligro (Paleocene of Argentina)

Also known as Chubut

Where: Chubut, Argentina (45.5° S, 67.2° W: paleocoordinates 48.1° S, 56.3° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Hansen Member (Salamanca Formation), Danian (66.0 - 61.6 Ma)

• Banco Negro Inferior, BN1; Peligran SALMA, considered to be middle Paleocene in age (Woodburne et al. 2014). "Marshall et al. (1981) indicated that a tuff in the upper part of the Hansen Member yielded a K-Ar date of 61±5 m.y." (Woodburne et al. 2014). This suggests the Peligran SALMA might be early Selandian in age.

•According to Andreis et al. (1975), the upper sectionof Salamanca Formation (= Hansen Member) in the San Jorge Gulf area was accumulated under infra-littoral and transitional sea conditions. The sediments were accumulated in low energy environments yielded by submarine bars or littoral banks that had reduced the circulation in a sea with little differences between high and low tides. Based on foraminifera, Bertels (1975) assigned the upper levels of the Salamanca Formation to the Upper Danian. This hypothesis was supported by the 40K/40A isotopic age of 61 ± 5Ma obtained from a vitreous tuff belonging to the Hansen Member at the Ca˜nad´on Hondo locality (Andreis 1977; Marshall et al. 1981). This age was subsequently corrected to 62.6 ± 5Ma byMarshall (1982). Additionally, two more reliable radiometric ages sampled by Marshall et al. (1981) in two basaltic units at or just under the base of the Salamanca Formation yielded ages of 64.0 ± 0.8Ma and 62.8 ± 0.8 Ma. Marshall et al. (1981, 1997) used these ages and palaeo-magnetic data to refer the overlaying BNI to polarity subchron C26r (= Danian Stage). PJW: I deleted "Peligran" from zone because that is a local stage name, too.

• group of beds-level stratigraphic resolution

Environment/lithology: mire or swamp; claystone and conglomerate

• brackish
• Package of dark sediments, comprising massive black clays with conchoidal fracture and some irregular conglomerates, with a whitish level of tuffaceous concretions on its lower part

Size classes: macrofossils, mesofossils

Preservation: original phosphate

Primary reference: R. Pascual, M. Archer, E. O. Jaureguizar, J. L. Prado, H. Godthelp and S. Hand. 1992. First discovery of monotremes in South America. Nature 356:704-706 [M. Uhen/M. Uhen]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 95914: authorized by Mark Uhen, entered by Mark Uhen on 05.05.2010, edited by Philip Mannion, Jelle Zijlstra, Evangelos Vlachos and Roger Benson

Creative Commons license: CC BY (attribution)

Taxonomic list

 Monotremata - Ornithorhynchidae
Monotrematum sudamericanum n. gen. n. sp.14
Monotrematum sudamericanum n. gen. n. sp.14 Pascual et al. 1992 platypus
 Allotheria - Sudamericidae
Sudamerica ameghinoi n. gen. n. sp.16 Scillato-Yane and Pascual 1984 mammal
UNP 79-II-18-1 - holotype (molariform)
Sudamerica ameghinoi15 Scillato-Yane and Pascual 1984 mammal
 Tribosphenida -
Placentalia indet. Owen 1837 placental
 Panameriungulata - Didolodontidae
Raulvaccia peligrensis n. gen. n. sp.10, Escribania talonicuspis n. sp.11, Escribania chubutensis n. gen. n. sp.11
Raulvaccia peligrensis n. gen. n. sp.10 Bonaparte et al. 1993 placental
Escribania talonicuspis n. sp.11 Gelfo et al. 2007 placental
MPEF-PV 1861 - type (well preserved m3 with complete roots and with well-preserved cusps)
Escribania chubutensis n. gen. n. sp.11 Bonaparte et al. 1993 placental
UNPSJB PV 916 - holotype (left jaw fragment with m2–3); hypodigm material: MLP 93–XII–10–2 (left m2), MPEF-PV 1860 (right jaw fragment with m1–2), MLP 93–XII- 10–1 (right jaw fragment with m3), MLP 90–II-12–67 (broken left m3 with the distal root and complete talonid), MLP 90–II-12–63 (right maxillary fragment with m2–3), MLP 90–II- 12–68 (left maxillary fragment with m2); referred material: MPEF-PV 1860 (right jaw fragment), MLP 93–XII-10–1 (right jaw fragment), MLP 90–II-12–67 (left m3) and MLP 90–II-12–63 (right maxillary fragment)
 Panameriungulata - Notonychopidae
Requisia vidmari n. gen. n. sp.7
Requisia vidmari n. gen. n. sp.7 Bonaparte and Morales 1997 placental
UNPSJB Pv 944 - holotype (right maxilla with teeth); hypodigm: UNPSJB Pv 945 (left maxilla); referred material: UNPSJB Pv 946 and 947 (teeth)
 Tribosphenida -
Metatheria indet.9 metatherian
MPEF-PV 2235 (right petrosal); "an edentulous fragment of a dentary of an 'opossum-like' form, slightly larger than Derorhynchus aff. D. minutus."
 Metatheria -
 Polydolopimorphia - Bonapartheriidae
Bonapartheriidae sp.9 Pascual 1980 metatherian
 Tribosphenida - Sternbergiidae
Didelphopsis sp.9 Paula Couto 1952 marsupial
 Tribosphenida - Derorhynchidae
Derorhynchus aff. minutus9 Goin et al. 1999 marsupial
 Metatheria -
cf. Sparassodonta indet.9 Ameghino 1894 metatherian
"an isolated astragalus probably belonging to a medium sized sparassodont"
 Meridiolestida - Mesungulatidae
Peligrotherium tropicalis n. gen. n. sp.12
Peligrotherium tropicalis n. gen. n. sp.12 Bonaparte et al. 1993 mammal
UNPSJB PV 914 - holotype (right dentary with m1 and m2); hypodigm: fragment of anterior left dentary with a not clear number of alveolus (MACNCH 1506); fragment of right dentary with m2 and part of m3-5 (MACN-CH 1501); fragment of left dentary with m2-5 alveoli (MACN-CH 1502); left mandibular fragment with m2-5 alveoli (MACN-CH 1503); fragment of right dentary with fragmentary roots of m2 and alveoli of m3-5 (MACN-CH 1504); left dentary fragment with m3-5 alveolus (MACN-CH 1505); maxillaries fragments with right M1-M2, and left M1 fragment, M2-M4 and fragmentary alveolus of M5 (MLP 90-II-12-58); right dentary fragment with distal part of m1 alveolus, m2, and fragmentary alveolus of m3 (MLP 90-II-12-60); right isolated tooth, probably p4 (MLP 90-II-12-61)
 Crocodylia - Alligatoridae
Caimaninae indet.8 Brochu 1999 crocodilian
Material originally described by Kuhn (1933) and although Simpson (1937) suspected a close affinity with Necrosuchus, he stopped short of making a formal referral (Brochu 2011)
Caimaninae indet.8 Brochu 1999 crocodilian
Protocaiman peligrensis n. gen. n. sp.6 Bona et al. 2018 crocodilian
MLP 80-X-10-1 - holotype
aff. Allognathosuchus sp. Mook 1921 crocodilian
 Eosuchia - Sphenodontidae
Kawasphenodon peligrensis n. sp.3 Apesteguía et al. 2014 lepidosaur
MPEF PV 1989 - holotype (incomplete left lower jaw preserving two teeth); MPEF PV1990 - paratype (incomplete right lower jaw preserving four teeth)
 Testudinata -
Peligrochelys walshae n. gen. n. sp.17
Peligrochelys walshae n. gen. n. sp.17 Sterli and de la Fuente 2013 turtle
MACN-PV CH 2017 - holotype (several skull bones (basisphenoid, basioccipital, right quadrate, right prootic, left opisthotic, a fragment of the right opisthotic, left exoccipital, right frontal, both postorbitals, fragment of left maxilla, fragments of both squamosals and other skull roof] and a left prezygapophysis); referred material: MPEF-PV 3975 (basisphenoid and basioccipital), MPEF-PV 3976 (right frontal) and MACN-2018 (left frontal)
 Testudines -
"Chelonia indet." = Testudines
"Chelonia indet." = Testudines Batsch 1788 turtle
chelid turtles
 Testudines - Chelidae
Trionyx argentina n. sp.2 Ameghino 1889 sideneck turtle
Original publication does not state the locality. Added to this locality following Wood and Paterson (1973) and Agnolin (2005).
"? Naiadochelys maior" = Yaminuechelys maior5 Staesche 1929 sideneck turtle
Staesche (1929); originally misspelled as Najadochelys
"Osteopygis sculptus n. sp." = Yaminuechelys maior5 Staesche 1929 sideneck turtle
Staesche (1929)
Naiadochelys cf. patagonica5 Staesche 1929 sideneck turtle
Staesche (1929); originally misspelled as Najadochelys
Naiadochelys patagonica n. sp.5 Staesche 1929 sideneck turtle
Staesche (1929); originally misspelled as Najadochelys
Hydromedusa cf. casamayorensis11 de la Fuente and Bona 2002 sideneck turtle
 Testudines - Panchelidae
Salamanchelys palaeocenica4 Bona 2006 sideneck turtle
Staesche (1929)
 Salientia - Calyptocephalellidae
Calyptocephalella sabrosa n. sp.13 Muzzopappa et al. 2021 helmeted water toad
Gigantobatrachus casamiquelai n. sp.1 Agnolin 2012 frog
 Salientia - Pipidae
? Pipidae indet.11 Gray 1825 clawed frog