Aguja Formation
Age
The ages of the Aguja Formation and its primary fossil-bearing unit, the Alto Shale, are not well understood. Due to the presence of the ammonite Baculites mclearni, which only occurs from 80.67 - 80.21 Ma, in the underlying Rattlesnake Mountain Sandstone and the Terlingua Creek Sandstone, it is likely that the Upper Shale was younger than 80.2 Ma. A radiometric date of 76.9 Ma was recovered in the Alto Shale, making it likely the formation wasn't younger than 76.9 Ma. The contact with the overlying Javelina Formation has been estimated at about 70 Ma ago but also as recently as 68.5 million years ago. This is unlikely, however, due to the presence of Bravoceratops, more primitive than an unnamed chasmosaurine from the De-na-zin Member of the Kirtland Formation, in the lowermost section of the formation. The age of the La Basa Sandstone is constrained by the presence of Scaphites hippocrepis III in the overlying Pen Formation which has been dated as old as 81.53 Ma.
Paleofauna
Reptiles
2 fragmentary caudal vertebrae of indeterminate reptiles are known from the Rattlesnake Mountain sandstone member.
Ornithischians
Ornithischians of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Agujaceratops | A. mariscalensis | Texas | Lower Alto Shale | Formerly considered a species of Chasmosaurus | ||
A. mavericus | West Texas | Middle Alto Shale | A chasmosaurine. | |||
Angulomastacator | A. daviesi | Texas | Middle Alto Shale | A left maxilla. | A lambeosaurine. | |
Ankylosauridae | Indeterminate | Texas | Lower Alto Shale | Osteoderms, vertebrae & limb elements. | Remains of an ankylosaurid, possibly represents Euoplocephalus sp. | |
Aquilarhinus | A. palimentus | Texas | Middle Abajo Shale | Partial skeleton | Formerly referred to Kritosaurus and Gryposaurus. | |
Ceratopsidae genus & species indeterminate | Indeterminate | West Texas | Middle Abajo Shale | Ilia, sacral vertebra & sacral ribs. | May represent Agujaceratops, but undiagnostic. | |
Chasmosaurus | C. mariscalensis | Texas | [Twelve] disarticulated skull (sic), postcrania, juvenile." | Considered by paleontologists Lucas, Sullivan, and Hunt to be distinct enough from the Chasmosaurus type species, C. belli to warrant being split off to a new genus, Agujaceratops. | ||
Edmontonia | E. sp | Texas | Lower Alto Shale | Osteoderm (TVP 45866-2) & skull (AMNH 3076). | A nodosaurid. | |
cf. Euoplocephalus | E. sp | Texas | Lower Alto Shale | Osteoderms, sacrum & vertebra (TL-05-14). | An ankylosaurid. | |
aff. Kritosaurus | K. navajovius | Texas | Upper Alto Shale | Two dentary teeth | Tooth crown morphology matches with Kritosaurus | |
Malefica | M. deckerti | Texas | Middle Alto Shale | A partial left maxilla. | Formerly referred to Kritosaurus. | |
Nodosauridae genus & species indeterminate | Indeterminate | West Texas | Middle Abajo Shale | Isolated & associated osteoderms. | Very similar to osteoderms of Invictarx. | |
Panoplosaurus | P. mirus | Texas | Lower Alto Shale | Osteoderm (TMM 45605-4). | A nodosaurid. | |
Saurolophinae | Indeterminate | Texas | Alto Shale | Various cranial and appendicular elements | Material from several localities previously referred to Kritosaurus but do not have its diagnostic features. | |
Saurolophinae | Indeterminate | Texas | Alto Shale | Various manual elements and vertebrae representing two individuals | Included in phylogenetic analyses as the "Big Bend OTU", most recently considered a kritosaurin | |
Stegoceras | S. sp. | West Texas | Middle Alto Shale | Frontal | A pachycephalosaur, represents a new unnamed species | |
Texacephale | T. langstoni | Texas | Lower Alto Shale | Two frontoparietal domes. | A pachycephalosaur. | |
Yehuecauhceratops | Y. mudei | Coahuila | A centrosaurine. |
Theropods
Indeterminate ornithomimid remains are known from the Upper Aguja Formation. Indeterminate tyrannosaurid fossils are known from the Upper Aguja Formation of Texas and Mexico.
Theropods of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Avialae incertae sedis | West Texas | Middle Abajo Shale | 4 teeth (TMM 45947-349, 350, 351). | A bird. | ||
Chirostenotes | C. sp. | Texas | Femur & manual ungual. | A caenagnathid | ||
Dromaeosauridae genus & species indeterminate | Indeterminate | West Texas | Middle Abajo Shale | Pedal phalanges (TMM 45909-2, TMM 44066-4). | A dromaeosaur. | |
cf. Dromaeosaurus | Indeterminate | Texas | ||||
Leptorhynchos | L. gaddisi | Texas | Lower Alto Shale | Dentaries, caudal vertebra & limb elements. | A caenagnathid | |
Ornithomimidae | New genus & species | West Texas | Middle Abajo Shale | Vertebrae, ischium & limb elements. | An unnamed species referred to informally as the 'Aguja ornithomimid'. | |
cf. Paronychodon | West Texas | Middle Abajo Shale | 2 incomplete teeth (TMM 45947-362). | A maniraptoran. | ||
Richardoestesia | R. cf. gilmorei | Texas | Low Upper Shale | Fragment of a small tooth. | A coelurosaur. | |
R. isosceles | Big Bend National Park, Texas | Low Upper Shale | Teeth. | A coelurosaur. | ||
Saurornitholestes | S. cf. langstoni | Texas | Lower Alto Shale & Middle Abajo Shale | Teeth. | A dromaeosaur, Teeth can belong to different taxa. | |
S. langstoni | Coahuila | Teeth | ||||
Saurornitholestes sp. | Coahuila | Teeth | ||||
Theropoda incertae sedis | Morphotype A | West Texas | Alto Shale | 8 teeth. | Unserrated, recurved teeth. | |
Morphotype B | West Texas | 5 tooth crowns. | Bi-serrated teeth. | |||
Morphotype C | West Texas | 7 teeth. | Finely serrated, distal plication only. | |||
Morphotype D | West Texas | 5 teeth. | Short, coarsely serrated distal plication. | |||
Morphotype E | West Texas | A tooth. | Strongly recurved, serrated distal plication. | |||
Morphotype F | West Texas | 2 tooth fragments. | Medium size, finely serrated plications. | |||
cf. Troodon | Indeterminate | Texas | ||||
Tyrannosauridae | Indeterminate | West Texas | Lower Alto Shale & Middle Abajo Shale | Isolated teeth & a handful of non-dental specimens. | Postcranial remains suggest a relatively small & gracile tyrannosaurid, considered a member of the Teratophoneini |
Sauropods
Indeterminate titanosaurid remains are known from the Upper Aguja Formation of Mexico.
Sauropods of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Titanosauridae | Indeterminate | Chihuahua | Four partial posterior caudal vertebrae & dorsal or sacrocaudal vertebra | A relatively massive titanosaurid. |
Crocodylomorphs
Crocodylomorphs of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Crocodilia | Indeterminate | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | Teeth. | A crocodilian. | |
Deinosuchus | D. riograndensis | Texas, Chihuahua, and Coahuila | Upper Shale | Multiple partial skulls & skeletons accounting for nearly the entire skeleton minus the tail. | A giant alligatoroid. | |
cf. D. sp. | West Texas | Middle Abajo Shale | Cervical osteoderm (TMM 44068-2). | An alligatoroid. | ||
Goniopholididae | New genus & species | West Texas | Middle Abajo Shale | Partial skull & skeleton along with isolated osteoderms & teeth. | May pertain to Denazinosuchus or a related taxon. | |
Phobosuchus | P. riograndensis | Texas, Chihuahua, and Coahuila | Reclassified as a Deinosuchus species |
Turtles
Testudines of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Adocus | A. sp. | Big Bend National Park, Texas. | Upper Shale | Shell fragments. | An adocid. | |
Baenidae | Big Bend National Park, Texas. | Upper Shale | Shell fragments. | 2 morphotypes present (A & B). | ||
Basilemys | B. sp. | Big Bend National Park, Texas. | Upper Shale & Lower Shale | Shell fragments, partial plastron & leg scutes. | A nanhsiungchelyid. | |
Bothremydidae genus & species indeterminate | Indeterminate | West Texas | Lower Shale | Isolated peripheral bones (TMM 44068-1, 42452-8); costal bones (TMM 44064-6). | A bothremydid, compatible with Chupacabrachelys. | |
Chupacabrachelys | C. complexus | Big Bend, Texas. | Base of the Upper Shale | A complete skull, and a nearly complete skeleton. | A bothremydid. | |
cf. Denazinemys | cf. D. sp. | West Texas | Lower Shale | Shell elements. | A baenid. | |
cf. Helopanoplia | Big Bend National Park, Texas. | Upper Shale | Shell fragments. | A softshell turtle. | ||
cf. Hoplochelys | Big Bend National Park, Texas. | Upper Shale | Shell fragments. | A kinosternoid. | ||
Terlinguachelys | T. fischbecki | Big Bend National Park, Texas | Rattlesnake Mountain Sandstone | A large, incomplete specimen. | A protostegid. | |
Testudines indeterminate | Morphotype 1 | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | A shell fragment. | ||
Morphotype 2 | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | A shell fragment. | |||
Morphotype 3 | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | A shell fragment. | |||
Morphotype 4 | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | A shell fragment. | |||
Trionychidae | Gen. et. sp. indet. | Big Bend National Park, Texas. | Upper Shale & Lower Shale | Costal bone (TMM 44068-4) & shell fragments. | A softshell turtle. |
Lepidosaurs
Lepidosaurs of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Anguidae | Gen. et. sp. indet. | Texas. | Isolated osteoderms & partial right frontal. | An anguid. | ||
Apsgnathus | A. triptodon | Brewster County, Texas. | Jaw elements. | A scincomorph. | ||
Catactegenys | C. solaster | Brewster County, Texas. | Jaw elements & teeth. | A night lizard. | ||
Dryadissector | D. shilleri | West Texas. | Middle Abajo Shale | Numerous isolated teeth. | A varanoid. | |
Mosasauridae | Indeterminate | Ten Bits Ranch. | Rattlesnake Mountain sandstone member. | 1 partial vertebra. | A mosasaur. | |
Odaxosaurus | O. piger | Brewster County, Texas. | Jaw elements. | An anguid. | ||
cf. Parasaniwa | cf. P. wyomingensis | Texas. | Jaw fragments. | A platynotan. | ||
Platynota | Gen. et. sp. indet. | Texas. | Dorsal vertebra (TMM 43057-332). | A platynotan. | ||
?Scincidae | Gen. et. sp. indet. | Brewster County, Texas. | Jaw elements. | A possible skink. | ||
cf. Scincomorpha | Gen. et. sp. indet. | Brewster County, Texas. | Jaw elements. | A scincomorph. | ||
Serpentes | Gen. et. sp. indet. | Texas. | Partial left dentary & right maxilla. | A snake. | ||
cf. Xenosauridae | Texas. | Osteoderms & maxillae. | A knob-scaled lizard. |
Mammals
Mammals of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Alphadon | A. perexiguus | Brewster County, Texas | Upper Shale | A metatherian. | ||
Paleomolops | P. langstoni | Brewster County, Texas | Upper Shale | A tribosphenidan; "cannot be confidently allied with either marsupials or eutherians". |
Bony fish
A diversity of bony fish, comprising both marine (Ten Bits/Rattlesnake Mountain locality) and freshwater (Lowerverse/Lower Shale locality) taxa, is known. Approximately 75 whole and broken fragments of coprolites are known from the Rattlesnake Mountain sandstone member, presumably from bony fish.
Bony fish of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Acanthomorpha indet. | family indet.
genus et sp. indet. |
Lowerverse, west Texas | Lower Shale | Vertebral centra. | An acanthomorph. | |
Acanthopterygii indet. | order indet.
family indet. genus et sp. indet. |
Lowerverse, west Texas | Lower Shale | Vertebral centra. | An acanthopterygian. | |
Acanthopterygian fin spine morph 1 | Fin spines | |||||
Acanthopterygian fin spine morph 2 | ||||||
Acanthopterygian fin spine morph 3 | ||||||
Acanthopterygian fin spine morph 4 | ||||||
Euacanthopterygian fin spine morph 1 | ||||||
Euacanthopterygian fin spine morph 2 | ||||||
Albula | A. sp. | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | Over 390 complete and fragmentary teeth. | A bonefish. | |
Lowerverse, west Texas | Lower Shale | |||||
Amiidae indet. | genus et sp. indet. | Lowerverse, west Texas | Lower Shale | Vertebral centra. | An amiid. | |
?Anomoeodus | ?A. sp. | Lowerverse, west Texas | Lower Shale | Isolated tooth crown | A pycnodont. Likely transported out of a marine habitat. | |
Atractosteus | A. sp. | Lowerverse, west Texas | Lower Shale | Teeth, jaw fragments, vertebral centra, scales. | A gar. | |
Clupeiformes indet. | family indet.
genus et sp. indet. |
Lowerverse, west Texas | Lower Shale | Vertebral centra. | A clupeiform. | |
cf. Cyclurus | cf. C. sp. | Lowerverse, west Texas | Lower Shale | 5 fragmentary tooth plates with teeth. | An amiid. | |
Ellimmichthyiformes indet. | family indet.
genus et sp. indet. |
Lowerverse, west Texas | Lower Shale | Vertebral centra. | An ellimmichthyiform. | |
Elopiformes indet. | family indet.
genus et sp. indet. |
Lowerverse, west Texas | Lower Shale | Vertebral centra | An elopiform. | |
?Enchodus | ?E. sp. | Ten Bits ranch, west Texas. | Rattlesnake Mountain sandstone member. | 2 abraded teeth. | An aulopiform. | |
Lowerverse, west Texas | Lower Shale | 4 isolated teeth. | ||||
Eotexachara | E. malateres | Lowerverse, west Texas | Lower Shale | Dentaries. | A characiform. | |
?Gonorynchiformes indet. | family indet.
genus et sp. indet. |
Lowerverse, west Texas | Lower Shale | Cranial bone, vertebral centrum, basibranchial. | A gonorynchiform. | |
Hiodontidae indet. | genus et sp. indet. | Lowerverse, west Texas | Lower Shale | Vertebral centra. | A hiodontiform. | |
Lepidotes | ?L. sp. | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | Approximately 109 complete and fragmentary teeth. | A lepidotid. | |
cf. Melvius | cf. M. sp. | Lowerverse, west Texas | Lower Shale | Vertebrae, 13 isolated teeth. | An amiid. | |
Micropycnodon | M. sp. | Lowerverse, west Texas | Lower Shale | 4 isolated teeth | A pycnodont. Likely transported out of a marine habitat. | |
Osteichthyes indet. | Indeterminate species A | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 11 complete teeth. | A bony fish. | |
Indeterminate species B | 8 complete and fragmentary teeth. | |||||
Indeterminate species C | 1 complete tooth. | |||||
Indeterminate species D | 1 complete and 1 partial tooth. | |||||
Indeterminate | Approximately 475 complete and fragmentary teleost centra. | |||||
Tooth morph 1 | Lowerverse, west Texas | Lower Shale | Teeth | |||
Tooth morph 2 | ||||||
Centrum morph 1 | Vertebral centra. | |||||
Centrum morph 2 | ||||||
Centrum morph 3 | ||||||
Centrum morph 4 | ||||||
Ostariophysi indet. | order indet.
family indet. genus et sp. indet. |
Lowerverse, west Texas | Lower Shale | Vertebral centra. | An ostariophysian. | |
Paralbula | P. cf. casei | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | Approximately 900 complete and fragmentary teeth and tooth caps. | A bonefish. Lowerverse specimens likely transported out of a marine habitat. | |
Lowerverse, west Texas | Lower Shale | |||||
Primuluchara | P. laramidensis | Lowerverse, west Texas | Lower Shale | Dentaries. | A characiform. | |
Stephanodus | ?S. sp. | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 21 whole and fragmentary specimens. | A pycnodont. | |
?Wilsonichthys | ?W. sp. | Lowerverse, west Texas | Lower Shale | Vertebral centra. | An osteoglossiform. | |
Cartilaginous fish
Cartilaginous fish of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Brachyrhyzodus | B. wichitaensis | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 11 complete teeth. | ||
Cantioscyllium | C. aff. meyeri | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 1 anterior tooth and 5 lateral teeth. | A nurse shark. | |
Chiloscyllium | C. aff. greeni | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | Approximately 90 abraded and fragmentary teeth. | A bamboo shark. | |
Chondrichthyes | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 23 placoid scales and 69 dermal scales. | 4 morphotypes of placoid scales (A to D) present. | ||
Columbusia | C. sp. | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 20 complete & fragmentary teeth. | A wobbegong. | |
Cretalamna | C. appendiculata | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 3 fragmentary teeth. | Reassigned to C. cf. C. sarcoportheta. | |
C. cf. C. sarcoportheta | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 3 incomplete teeth & fragments of additional teeth. | Originally reported as C. appendiculata. | ||
Cretorectolobus | C. olsoni | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | "20 complete and fragmentary teeth". | A carpet shark. | |
Hybodontidae genus & species indeterminate | Indeterminate | West Texas | Lower Shale | Fragment of a dorsal fin spine (TMM 42536-10). | A hybodont. | |
Hybodus | H. sp. | Ten Bits Ranch. | Rattlesnake Mountain sandstone member. | 2 specimens, one complete and one partial tooth. | A hybodont. | |
Igdabatis | I. indicus? | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | A single incomplete tooth. | A myliobatid. | |
Ischyrhiza | I. cf. avonicola | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 5 complete and fragmentary rostral teeth. | A sawskate. | |
I. mira | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 11 fragmentary rostral teeth and 230 whole and fragmentary oral teeth. | A sawskate. | ||
Lonchidion | L. selachos | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 4 complete and 5 fragmentary teeth. | A hybodont. | |
Meristodon | M. sp. | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 2 teeth. | A hybodont. | |
Myliobatiformes | Incertae sedis | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 3 complete specimens. | ||
Protoplatyrhina | P. renae | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 70 complete and fragmentary teeth. | A hypsobatid. | |
Ptychotrygon | P. agujaensis | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | Over 690 complete and fragmentary teeth. | A sawskate. | |
P. triangularis | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | Over 170 complete and fragmentary teeth. | A sawskate. | ||
P. aff. cuspidata | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 7 whole and fragmentary teeth. | A sawskate. | ||
P. sp. | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | One complete tooth (TMM 46018-71). | A sawskate. | ||
Rhinobatos | R. casieri | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | "14 complete and fragmentary specimens". | A guitarfish. | |
R. sp. | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 18 complete & fragmentary specimens. | A guitarfish. | ||
Rhombodus | R. levis | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | Over 22 complete and fragmentary teeth. | A rajiforme. | |
Scapanorhynchus | S. texanus | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | Over 800 complete and fragmentary teeth. | A mitsukurinid. | |
Sclerorhynchidae | Morphotype 1 | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | One fragmentary rostral spine (TMM 46018-59). | A sawskate. | |
Morphotype 2 | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | One fragmentary rostral spine (TMM 46018-60). | A sawskate. | ||
Morphotype 3 | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 3 fragmentary rostral teeth. | A sawskate. | ||
Morphotype 4 | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 27 fragmentary rostral spines. | A sawskate. | ||
Serratolamna | S. cf. S. caraibaea | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | About 34 teeth. | A mackerel shark. | |
Squalicorax | S. kaupi | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | "26 complete and fragmentary anterior and lateral teeth". | An anacoracid. | |
S. aff. S. lindstromi | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 4 specimens. | An anacoracid. | ||
S. pristodontus | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 2 specimens. | An anacoracid. | ||
S. aff. S. yangaensis | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 4 complete & several fragmentary teeth. | An anacoracid. | ||
Squatina | S. hassei | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | A single complete specimen. | An angelshark. | |
S. sp. | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | A complete tooth & 2 fragmentary teeth. | An angelshark. | ||
Texatrygon | T. cf. T. copei | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 4 complete & fragmentary teeth. | A sawskate formerly reported as T. hooveri. | |
T. hooveri | Ten Bits Ranch, west Texas. | Rattlesnake Mountain sandstone member. | 4 complete and fragmentary specimens. | Reassigned to T. cf. T. copei. |
Invertebrates
Ammonites
Ammonites of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Abundance | Notes | Images |
Baculites | B. mclearni |
|
||||
Hoplitoplacenticeras | H. plasticum | Rattlesnake Mountain Sandstone | ||||
Pachydiscus | P. paulsoni | Rattlesnake Mountain Sandstone |
Plants
Plants of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Sabal | S. bigbendense | Big Bend National Park, Texas. | Upper Shale | 4 seeds. | A palm. It has the largest seeds of any fossil Sabal. | |
S. bracknellense | Big Bend National Park, Texas. | Upper Shale | 5 seeds. | A palm. The seeds are indistinguishable from those of Eocene S. bracknellense, and so were assigned to that species. However, it is likely these Aguja palms would be found to represent distinct species if other parts of the plants were available for comparison. |
Color key
|
Notes Uncertain or tentative taxa are in small text; |
See also
References
- ^ Weishampel et al., 2004, "Dinosaur distribution (Late Cretaceous, North America).", pp.574-588
- ^ Manchester, Steven R.; Lehman, Thomas M.; Wheeler, Elisabeth A. (July 2010). "Fossil Palms (Arecaceae, Coryphoideae) Associated with Juvenile Herbivorous Dinosaurs in the Upper Cretaceous Aguja Formation, Big Bend National Park, Texas". International Journal of Plant Sciences. 171 (6): 679–689. doi:10.1086/653688. ISSN 1058-5893. S2CID 84762968.
- ^ Fowler, Denver Warwick (2017-11-22). "Revised geochronology, correlation, and dinosaur stratigraphic ranges of the Santonian-Maastrichtian (Late Cretaceous) formations of the Western Interior of North America". PLOS ONE. 12 (11): e0188426. Bibcode:2017PLoSO..1288426F. doi:10.1371/journal.pone.0188426. ISSN 1932-6203. PMC 5699823. PMID 29166406.
- ^ Woodward, H. N. (2005). Bone histology of the sauropod dinosaur Alamosaurus sanjuanensis from the Javelina Formation, Big Bend National Park, Texas.
- ^ Sankey, J. (2010). Faunal composition and significance of high–diversity, mixed bonebeds containing Agujaceratops mariscalensis and other dinosaurs, Aguja Formation (Upper Cretaceous), Big Bend, Texas. In New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium (pp. 520-537).
- ^ Fowler, Denver W.; Fowler, Elizabeth A. Freedman (2020-06-05). "Transitional evolutionary forms in chasmosaurine ceratopsid dinosaurs: evidence from the Campanian of New Mexico". PeerJ. 8: e9251. doi:10.7717/peerj.9251. ISSN 2167-8359. PMC 7278894. PMID 32547873.
- ^ Prieto-Márquez, Albert; Wagner, Jonathan R.; Lehman, Thomas (2020-03-18). "An unusual 'shovel-billed' dinosaur with trophic specializations from the early Campanian of Trans-Pecos Texas, and the ancestral hadrosaurian crest" (PDF). Journal of Systematic Palaeontology. 18 (6): 461–498. Bibcode:2020JSPal..18..461P. doi:10.1080/14772019.2019.1625078. ISSN 1477-2019. S2CID 202018197.
- ^ Schubert, Joseph (May 2013). Elasmobranch and osteichthyan fauna of the Rattlesnake Mountain Sandstone, Aguja Formation (Upper Cretaceous; Campanian), West Texas (Thesis thesis).
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Bibliography
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