Pajcha Pata: Late/Upper Maastrichtian, Bolivia
collected by Marshall, Gayet and Meunier 1989, 1994

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
unclassified
Latinopollia suarezi
Lepidotyle enigmatica
scales, ?fragments of neurocranial bones, rostrum
Phaerodusichthys taverni
fragments of mandibles, anterior part of a premaxilla
Serrasalminae informal indet. 1
isolated teeth
Serrasalminae informal indet. 3
isolated teeth
Arioida informal new genus
fragments of dermal cranium and of pectoral and dorsal spines; 'new genus;
Santosius sp.
3 specimens
3 spiny parts of preoperculum
Serrasalminae informal indet. 2
isolated teeth
    = Acnodon sp.
Ballen et al. 2022
Dipnoi - Ceratodontidae
Ceratodus sp. Agassiz 1838
3 specimens
3 tooth plates
Dipnomorpha - Lepidosirenidae
Lepidosiren cf. paradoxa Fitzinger 1837
Gayet et al. 1991 4 specimens
3 pterygoid, 1 prearticular tooth plates
Mammalia
Mammalia informal indet. 2 Linnaeus 1758
1 specimen
1 upper right tooth, "gen. et sp. indet. 2"
Mammalia - Dryolestidae
? Dryolestoidea informal indet. 1
1 specimen
1 upper right molar: The overall molar morphology is consistent with a tribosphenic mammal, while dryolestoid affinities are suggested; "Mammalia gen. et sp. indet. 1"
    = Dryolestidae sp. Marsh 1879
Kielan-Jaworowska et al. 2004
Mammalia
? Theria informal indet. 3 (Parker and Haswell 1897)
1 specimen
fragment of an upper molar: This specimen is tentatively regarded as a non-tribosphenid therian largely by exclusion from other groups as well as showing clear evidence of cusp structure. "Mammalia gen. et sp. indet. 3"
    = Eutheria sp. Huxley 1880
Kielan-Jaworowska et al. 2004
Reptilia - Testudines - Podocnemidae
Chelonia indet. (Latreille 1800)
Gayet et al. 1991
    = Podocnemidae indet. Cope 1868
Gayet et al. 2001
original and current combination Podocnemididae
Numerous fragments of turtle plates were observed in the field and some of them collected, but all were regarded as indeterminate podocnemidids
Reptilia - Madtsoiidae
Serpentes indet. Linnaeus 1758
Gayet et al. 1991
    = ? Madtsoiidae indet. Hoffstetter 1961
Gayet et al. 2001
Two incomplete trunk vertebrae (Fig. 14) apparently belong to the same species. Parazygantral foramina apparently present; such foramina characteristic of the Madtsoiidae. Whatever its correct family referral is, this snake represents a new genus
Reptilia - Abelisauridae
Coelurosauria indet. Huene 1914
Marshall 1989 1 specimen
1 tooth (MHNC-3702); numerous tooth fragments
    = Abelisauridae indet. Bonaparte and Novas 1985
Gianechini and Apesteguía 2012
Reptilia
Sauropoda indet. (Marsh 1878)
tooth fragments
Reptilia - Crocodylia
Crocodylia indet. (Owen 1842)
Gayet et al. 1991
Amphibia - Temnospondyli
Gymnophiona indet. Rafinesque 1814
7 specimens
7 vertebrae (Gayet et al 2001)
Amphibia - Temnospondyli - Urodela
Noterpeton bolivianum n. gen., n. sp. Rage et al. 1993
Rage et al. 1993 38 specimens
Amphibia - Temnospondyli
Anura indet. (Fischer von Waldheim 1813)
Gayet et al. 1991
3 presacral vertebrae (Gayet et al 2001)
Cladistia - Polypteriformes - Polypteridae
Dagetella sudamericana Gayet and Meuniere 1992
isolated scales, neurocranial elements, spines of finlets, and vertebrae
Actinopteri - Lepisosteiformes - Lepisosteidae
Lepisosteus sp. Agassiz 1843
Gayet et al. 1991
isolated scales, 1 vertebra (Gayet et al 2001)
Actinopteri - Pycnodontiformes - Pycnodontidae
Pycnodontidae indet. (Agassiz 1833)
numerous teeth
Coelodus toncoensis
Gayet et al. 1991
fragments of splenial bones, two vomerian bones, teeth (Gayet et al 2001)
Actinopteri - Perciformes - Latidae
Latidae indet.
2 fragments of mandible; several vertebra; "new genus"
Actinopteri - Tetraodontiformes - Eotrigonodontidae
Stephanodus minimus
numerous pharyngeal and incisiform teeth
Actinopteri - Cyprinodontiformes
cf. Cyprinodontiformes indet. Bertin 1958
Gayet et al. 1991
Actinopteri - Aulopiformes - Enchodontidae
Enchodus sp. Agassiz 1835
isolated teeth
Actinopteri - Siluriformes
Siluriformes indet.
fragments of pectoral and dorsal spines
Actinopteri - Siluriformes - Siluridae
Rhineastes sp. Cope 1872
Gayet et al. 1991
Actinopteri - Siluriformes - Andinichthyidae
Andinichthyidae indet. Gayet 1988
Gayet et al. 1991
Andinichthys sp. Gayet 1988
more or less complete pectoral and dorsal spines
Actinopteri - Characiformes
Characoidei indet.
fragment of mandible, isolated lower and/or upper jaws, 'new genus'; "new genus"
Actinopteri - Characiformes - Characidae
Tetragonopterinae indet. Lundberg 1997
numerous isolated teeth
Actinopteri - Ellimmichthyiformes - Gasteroclupeidae
Gasteroclupea branisai Signeux 1964
Gayet et al. 1991
Actinopteri - Osteoglossiformes - Osteoglossidae
Heterotidinae indet. Nelson 1968
fragments of mandibles, squamules
Chondrichthyes - Rajiformes - Sclerorhynchidae
Pucapristis branisi Schaeffer 1963
Gayet et al. 1991 4 specimens
4 oral teeth (Gayet et al 2001)
Ischyrhiza hartenbergeri Cappetta 1975
32 specimens
22 oral teeth, 10 fragmentary teeth
Chondrichthyes - Myliobatiformes - Dasyatidae
Dasyatis schaefferi Cappetta 1975
8 specimens
8 oral teeth
Dasyatis molinoensis Cappetta 1975
3 specimens
three oral teeth
Dasyatis branisai Cappetta 1975
4 specimens
4 oral teeth
Chondrichthyes - Myliobatiformes - Rhombodontidae
Pucabatis hoffstetteri Cappetta 1975
Gayet et al. 1991 74 specimens
74 oral teeth (Gayet et al 2001)
see common names

Geography
Country:Bolivia State/province:Cochabamba
Coordinates: 17.7° South, 65.9° West (view map)
Paleocoordinates:20.2° South, 52.0° West
Basis of coordinate:based on nearby landmark
Altitude:2628 meters
Geographic resolution:outcrop
Time
Period:Cretaceous Epoch:Late/Upper Cretaceous
Stage:Maastrichtian 10 m.y. bin:Cretaceous 8
*Period:Late/Upper Cretaceous - Late/Upper Cretaceous *Epoch:Senonian
*International age/stage:Maastrichtian - Maastrichtian
Key time interval:Late/Upper Maastrichtian
Age range of interval:72.10000 - 66.00000 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Geological group:Puca Formation:El Molino Member:Lower
Stratigraphic resolution:bed
Stratigraphy comments: The fossils described in this paper occur about 30 m above the base of the El Molino Formation. This is in the base of the upper part of the Lower Member of the El Molino Formation

Based on a detailed study of the magnetostratigraphy of the El Molino Formation at the La Palca stratotype section near Potosı́, and applying sequence stratigraphic methods for correlating with the Pajcha Pata section, the fossil bed is ≈68.4 Ma (Sempere et al., 1997, following the time scale of [Cande and Kent, 1992] and [Cande and Kent, 1995]).
Lithology and environment
Primary lithology:fine,medium,red,yellow sandstone
Includes fossils?Y
Lithology description: The fossiliferous unit is about 3-m thick, and consists of red to yellow, fine- to medium-grained sandstone.The bed represents a broad channel that can be followed for about 2 km to the northeast of Pajcha Pata.
Environment:estuary/bay
Geology comments: The bed was deposited during a sharp and short regressive phase of the dominantly marine-influenced Lower El Molino at a time when deposition rates for the El Molino were highest. The channel sands derive from a large northeasterly draining river system
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils,mesofossils
Collection methods and comments
Collection excludes:some macrofossils
Collection methods:bulk,surface (float),sieve,field collection
Reason for describing collection:taxonomic analysis
Collectors:Marshall, Gayet and Meunier Collection dates:1989, 1994
Collection method comments: Museo de Historia Natural de Cochabamba, Cochabamba, Bolivia (MHNC) collection
Taxonomic list comments:The fossil remains found at Pajcha Pata are mostly vertebrates. Nevertheless, a small number of invertebrates and plants have been recovered. They are generally very small and poorly preserved. There are gastropods (internal casts that seem identical to those found at Vila Vila21 and Tiupampa28), and Bryozoa. The flora is composed of charophytes. Some fish taxa (Gasteroclupea, Atherinomorpha), already reported at Pajcha Pata ( [Gayet, 1991] and [Gayet et al., 1991]) do not come from the main level but are from the area that includes this locality discussed in this paper. Consequently, they are not discussed in this present work.
Metadata
Also known as:Pajchapata
Database number:12855
Authorizer:E. Fara, M. Carrano, G. Ballen, R. Benson Enterer:E. Fara, R. Benson, G. Ballen, M. Carrano
Modifier:G. Varnham Research group:vertebrate
Created:2001-12-20 08:33:48 Last modified:2022-01-28 09:27:09
Access level:group members Released:2002-03-20 08:33:48
Creative Commons license:CC BY
Reference information

Primary reference:
39674. M. Gayet, L. G. Marshall, T. Sempere, F. J. Meunier, H. Capetta and J. Rage. 2001. Middle Maastrichtian vertebrates (fishes, amphibians, dinosaurs and other reptiles, mammals) from Pajcha Pata (Bolivia). Biostratigraphic, palaeoecologic and palaeobiogeographic implications. Palaeogeography, Palaeoclimatology, Palaeoecology 169(1-2):39-68 [R. Benson/R. Benson]

Secondary references:

79450 G. A. Ballen, C. Jaramillo, F. C. P. Dagosta and M. C. C. Pinna. 2022. A fossil fish assemblage from the middle Miocene of the Cocinetas Basin, northern Colombia. Papers in Palaeontology 1-17 [G. Ballen/G. Ballen/G. Ballen]
19317ETE M. Gayet, L. G. Marshall, and T. Sempere. 1991. The Mesozoic and Paleocene vertebrates of Bolivia and their stratigraphic context: a review. In R. Suarez-Soruco (ed.), Fosiles y Facies de Bolivia. Volumen 1—Vertebrados. Revista Técnica de YPFB 12(3-4):393-433 [M. Carrano/M. Carrano]
76372 F. A. Gianechini and S. Apesteguía. 2012. Comments on the Pajcha Pata (Bolivia) theropod tooth. Reunión de Comunicaciones de la Asociacion Paleontológica Argentina. Resúmenes. Ameghiniana 49(4 (suppl.)):R145 [M. Carrano/M. Carrano/M. Carrano]
14365 Z. Kielan-Jaworowska, R. L. Cifelli, and Z.-X. Luo. 2004. Mammals from the age of dinosaurs: Origins, evolution, and structure. Columbia University Press, New York 1-630 [R. Whatley/R. Whatley/R. Whatley]
76346 L. G. Marshall. 1989. El primer diente de dinosaurio en Bolivia [The first dinosaur tooth in Bolivia]. Revista Técnica de Yacimientos Petroliferos Fiscales Bolivianos 10(3–4):129-130 [M. Carrano/M. Carrano]
42845% 16520J. -C. Rage, L.G. Marshall, and M. Gayet. 1993. Enigmatic Caudata (Amphibia) from the Upper Cretaceous of Gondwana. Géobios 26(5):515-519 [E. Fara/E. Fara/J. Alroy]
76345 M. Suárez Riglos, R. Céspedes Paz, and O. Medina Ramirez. 2019. Ruta de Migracíon de los Dinosaurios en Bolivia [Migration Route of Dinosaurs in Bolivia] 1-104 [M. Carrano/M. Carrano]