Mammalon Hill (Paleocene of the United States)

Also known as Bentonnie Tsosie Arroyo/Wash; Betonnie-Tsosie Arroyo; Bitonitsoseh Arroyo; Eduardo Arroyo; Nameless Arroyo; Sinclair and Sinclair and Granger Loc. 7; Tsosie Hill; NMMNH locality L-646; L-0646; UCMP V-2811, V-3860; UNM B77-7

Where: San Juan County, New Mexico (36.3° N, 108.2° W: paleocoordinates 43.2° N, 87.3° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Nacimiento Formation, Puercan (66.0 - 63.3 Ma)

• underlies Middle ("Upper") Kimbetoh

•from an interval about 8 to 16 m above the Ojo Alamo-Nacimiento contact that is entirely of normal polarity and therefore almost certainly represents chron C29n: Lindsay et al. 1981; this interval is just below the middle of the normal zone

• member-level stratigraphic resolution

Environment/lithology: terrestrial; lithology not reported

Size class: mesofossils

Collection methods: bulk, sieve

Primary reference: T. E. Williamson. 1996. The beginning of the age of mammals in the San Juan Basin, New Mexico; biostratigraphy and evolution of Paleocene mammals of the Nacimiento Formation. New Mexico Museum of Natural History and Science Bulletin 8:1-141 [J. Alroy/J. Alroy/P. Mannion]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 14760: authorized by John Alroy, entered by John Alroy on 30.04.1994, edited by K. Christopher Beard

Creative Commons license: CC BY (attribution)

Taxonomic list

• replaces list of Williamson and Lucas 1993, which included material from East Flank and West Flank of Kimbetoh Arroyo (see)
Williamson's list 16
although Williamson omits multis, they were described by Sloan 1981
following localities could be from either arroyo: LACM 5090, 5091, 5092, 5394, 5395, 5396; UALP 7631
Williamson and Lucas state that UCMP V-2811, 2813, and 3861 are in Barrel Spring Arroyo, but I consider it likely this is a lapsus
Lucas et al. 1981 claim that MH "Tetraclaenodon" and "pantodont" i.d.s of Rigby and Lucas 1981 are in error
a single interval of less than 8 m according to Lindsay et al. 1981
"? Procerberus sp." and new leptictid "A" are present only at Black Toe (see)

"Desmatoclaenus protogonioides" and "D. dianae" of Williamson and Lucas 1993 are actually from East Flank of Kimbetoh Arroyo (see)
 Squamata - Anguidae
Odaxosaurus piger8, "Proxestops jepseni" = Proxestops silberlingii8
Odaxosaurus piger8 Gilmore 1928 squamates
AMNH specimen from "the Puercan strata of Tsosie Wash"
"Proxestops jepseni" = Proxestops silberlingii8 Gilmore 1938 squamates
AMNH and LACM specimens from "Tsosie Wash/Mammalon Hill"
 Squamata -
Lacertilia indet.8 lizard
AMNH specimen from "Mammalon Hill"
 Theriamorpha - Peradectidae
? Peradectes sp. Matthew and Granger 1921 marsupial
"A": MH
 Theriamorpha - Herpetotheriidae
Thylacodon pusillus Matthew and Granger 1921 marsupial
AMNH 58230, right m2 or 3, left M1, partial M2 or 3
 Condylarthra - Hyopsodontidae
Valenia wilsoni3 Van Valen 1978 condylarth
figured specimen of Van Valen 1988 is from Tsosie Arroyo
Bubogonia bombadili n. sp. Van Valen 1978 condylarth
is from MH see Van Valen 1978
"Bomburia priscus" = Bomburodon priscus Matthew 1937 condylarth
AMNH 58377
"Platymastus palantir n. sp." = Bomburodon priscus9 Matthew 1937 condylarth
Tiznatzinia vanderhoofi Simpson 1936 condylarth
Choeroclaenus turgidunculus Cope 1888 condylarth
 Theriamorpha -
Erinaceomorpha indet. Gregory 1910 placental
close to Adunator: MH
 Acreodi - Triisodontidae
Eoconodon sp. Matthew and Granger 1921 placental
said to be new; "E. cf. copanus" from NMMNH 317 near MH
Eoconodon ginibitohia n. sp.2 Clemens and Williamson 2005 placental
from NMMNH loc. 317 "in the vicinity of Mammalon Hill"
Eoconodon coryphaeus Cope 1885 placental
Eoconodon gaudrianus Cope 1888 placental
 Theriamorpha - Periptychidae
Periptychus coarctatus Cope 1883 condylarth
presumably includes "Carsioptychus sp." of Lindsay et al. 1978 from MH
Ectoconus ditrigonus Cope 1882 condylarth
presumably includes "E. sp." of Lindsay et al. 1978 from MH; "E. majusculus" reported at lower Kimbetoh Arroyo by Simpson 1941e
Hemithlaeus kowalevskianus Cope 1882 condylarth
includes "H. sp." of Lindsay et al. 1978 from KA and MH
"Conacodon entoconus" = Haploconus entoconus Cope 1882 condylarth
Mithrandir gillianus1 Cope 1882 condylarth
Escatepos campi n. sp. Reynolds 1936 condylarth
see Reynolds 1936: S & G Loc. 7
Oxyacodon priscilla Matthew 1937 condylarth
found at KA "Ectoconus Zone" and UCMP V-2811, 3860: Archibald et al. 1983b
Oxyacodon apiculatus Osborn and Earle 1895 condylarth
found at UCMP V-2811: Archibald et al. 1983b
Oxyacodon agapetillus9 Cope 1884 condylarth
Conacodon kohlbergeri n. sp. Archibald et al. 1983 condylarth
from BLM loc. 1711 and "3 mi. E of Kimbetoh" according to Archibald et al. 1983b; presumably includes "C. sp." of Lindsay et al. 1978 from KA and MH
Conacodon cophater Cope 1884 condylarth
 Procreodi - Arctocyonidae
Oxyclaenus simplex Cope 1884 condylarth
Oxyclaenus cuspidatus Cope 1884 condylarth
Loxolophus hyattianus9 Cope 1885 condylarth
Loxolophus kimbetovius Matthew 1937 condylarth
 Cimolesta - Cimolestidae
"Cimolestes simpsoni n. sp." = Puercolestes simpsoni, "Puercolestes simpsoni" = Puercolestes simpsoni10, Betonnia tsosia n. gen. n. sp.10
"Cimolestes simpsoni n. sp." = Puercolestes simpsoni Reynolds 1936 eutherian
see Reynolds 1936: S & G Loc. 7
"Puercolestes simpsoni" = Puercolestes simpsoni10 Reynolds 1936 eutherian
"Genus B"; "? cf. Ictidopappus" of MacIntyre 1966; MH; discussions of Fox and Youzwyshyn 1994 and Williamson 1996 are compatible with Van Valen's identification
Betonnia tsosia n. gen. n. sp.10 Williamson et al. 2011 eutherian
NMMNH locality L-646
 Theriamorpha - Stylinodontidae
Wortmania otariidens5 Cope 1885 taeniodont
KA and MH
 Theriamorpha -
Onychodectes tisonensis5 Cope 1888 taeniodont
KA and MH; not clear why this is omitted by Williamson 1996
 Multituberculata - Eucosmodontidae
Eucosmodon primus n. sp.7 Sloan 1981 multituberculate
 Multituberculata - Taeniolabididae
Catopsalis foliatus4 Cope 1882 multituberculate
one specimen of "Eucosmodon primus" from MH, see Granger and Simpson 1929; also discussed by Lucas et al. 1997; type is from the "Hemithlaeus Zone" somewhere in the San Juan Basin, see Sloan 1981
 Multituberculata - Neoplagiaulacidae
Parectypodus vanvaleni n. sp.7 Sloan 1981 multituberculate
Neoplagiaulax macintyrei n. sp.7 Sloan 1981 multituberculate
Mesodma thompsoni7 Clemens 1964 multituberculate
 Multituberculata - Ptilodontidae
Ptilodus tsosiensis n. sp.7, Kimbetohia campi n. gen. n. sp.6
Ptilodus tsosiensis n. sp.7 Sloan 1981 multituberculate
Kimbetohia campi n. gen. n. sp.6 Simpson 1936 multituberculate
UCMP 31305 - holotype (skull fragment with left P2–4 and partial right P1); referred material: four isolated P4s (Sloan, 1981)