Aguja Formation
Aguja Formation | |
---|---|
Stratigraphic range: Lower to Middle Campanian ~ | |
![]() Outcrops of the Aguja Formation, Big Bend National Park, Texas | |
Type | Geological formation |
Unit of | Tornillo Group |
Sub-units | Upper Shale, Terlingua Creek Sandstone, Rattlesnake Mt. Sandstone, Lower Shale & Basal Sandstone Members |
Underlies | Javelina Formation |
Overlies | Pen Formation |
Lithology | |
Primary | Sandstone, conglomerate, claystone |
Other | Mudstone, shale, limestone |
Location | |
Coordinates | 29°18′N 103°30′W / 29.3°N 103.5°WCoordinates: 29°18′N 103°30′W / 29.3°N 103.5°W |
Approximate paleocoordinates | 35°48′N 77°00′W / 35.8°N 77.0°W |
Region | ![]() ![]() ![]() |
Country | ![]() ![]() |
The Aguja Formation is a geological formation in North America, exposed in Texas, United States and Chihuahua and Coahuila in Mexico, whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.[1] Fossil palms have also been unearthed here.[2]
Age
The ages of the Aguja Formation and its primary fossil-bearing unit, the Upper 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.[3] A radiometric date of 76.9 Ma was recovered in the Upper Shale, making it likely the formation wasn't younger than 76.9 Ma.[3] The contact with the overlying Javelina Formation has been estimated at about 70 Ma ago[4] but also as recently as 68.5 million years ago.[5] 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.[6] The age of the Basal 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.[3][7]
Vertebrate paleofauna
![](https://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Hadrosaur_bone_in_the_Aguja_Formation_by_Nick_Longrich.jpg/150px-Hadrosaur_bone_in_the_Aguja_Formation_by_Nick_Longrich.jpg)
Reptiles
2 fragmentary caudal vertebrae of indeterminate reptiles are known from the Rattlesnake Mountain sandstone member.[8]
Pseudosuchians
Crurotarsans of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Crocodilia[8] | Indeterminate[8] | Ten Bits Ranch.[8] | Rattlesnake Mountain sandstone member.[8] | Teeth. | ||
Deinosuchus[9] | D. riograndensis[9] | Texas,[9] Chihuahua, and Coahuila[10] | Osteoderm and mandible fragment | |||
Phobosuchus[9] | P. riograndensis[9] | Texas,[9] Chihuahua, and Coahuila | Reclassified as a Deinosuchus species |
Ornithischians
Ornithischians of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Agujaceratops[11] | A. mariscalensis[11] | Texas[11] | Low Upper Shale[12] | The type species, A. mariscalensis, was formerly considered a species of Chasmosaurus[11] | ||
A. mavericus[13] | Texas | |||||
Angulomastacator[14] | A. daviesi[14] | Texas[14] | ||||
Chasmosaurus[15] | C. mariscalensis[16] | Texas[16] | [Twelve] disarticulated skull (sic), postcrania, juvenile."[17] | 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.[11] | ||
Edmontonia[16] | E. sp[18][19] | Texas[16][19] | ||||
cf. Euoplocephalus[16] | E. sp[16][19] | Texas[16][19] | ||||
Panoplosaurus[19] | P. mirus[19] | Texas[19] | ||||
Aquilarhinus[20] | A. palimentus | Texas[16] | Formerly referred to Kritosaurus and Gryposaurus.[21] | |||
Kritosaurus[15] | Indeterminate[15] | Chihuahua[22] | ||||
Texacephale[23] | T. langstoni[23] | Texas[23] | Low Upper Shale[12] | |||
Yehuecauhceratops[24] | Y. mudei[25] | Coahuila[26] |
Theropods
Indeterminate ornithomimid remains are known from the Upper Aguja Formation.[27] Indeterminate tyrannosaurid fossils are known from the Upper Aguja Formation of Texas and Mexico.[28]
Theropods of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
cf. Tyrannosauridae[28] | Indeterminate[28] | Texas[28] | ||||
cf. Dromaeosaurus[29] | Indeterminate[29] | Texas[16] | ||||
Leptorhynchos | L. gaddisi | Texas[30] | A caenagnathid | |||
Ricardoestesia[31] | R. cf. gilmorei[32] | Texas[31] | ||||
R. isosceles[31] | Texas[31] | |||||
Saurornitholestes[16] | S. cf. langstoni[33] | Texas[16] | ||||
cf. Troodon[34] | Indeterminate[34] | Texas[16] |
Lepidosaurs
Lepidosaurs | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Mosasauridae[8] | Indeterminate[8] | Ten Bits Ranch.[8] | Rattlesnake Mountain sandstone member.[8] | 1 partial vetebra.[8] |
Turtles
Testudines of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Terlinguachelys[9] | T. fischbecki[9] | Texas | Rattlesnake Mountain Sandstone[9] | |||
Testudines indeterminate[8] | Morphotype 1[8] | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | A shell fragment. | ||
Morphotype 2[8] | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | A shell fragment. | |||
Morphotype 3[8] | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | A shell fragment. | |||
Morphotype 4[8] | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | A shell fragment. |
Bony Fish
Approximately 75 whole and broken fragments of coprolites are known from the Rattlesnake Mountain sandstone member, presumably from bony fish.[8]
Bony fish of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Albula[8] | A. sp.[8] | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "Approximately 385 complete and fragmentary teeth". | A bonefish. | |
Eotexachara[35] | E. malateres[35] | Dentaries.[35] | A characiform. | |||
Lepidotes[8] | L. sp.[8] | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "Approximately 106 complete and fragmentary teeth". | A lepidotid. | |
Osteichthyes[8] | Indeterminate species A | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 11 complete teeth. | ||
Indeterminate species B | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 8 complete and fragmentary teeth. | |||
Indeterminate species C | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 1 complete tooth. | |||
Indeterminate species D | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 1 complete and 1 partial tooth. | |||
Indeterminate | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | Approximately 462 complete and fragmentary teleost centra. | |||
Paralbula[8] | P. casei[8] | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "Approximately 130 complete and fragmentary teeth and tooth caps". | ||
Primuluchara[35] | P. laramidensis[35] | Dentaries.[35] | A characiform. | |||
Stephanodus[8] | S.?[8] | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "22 whole and fragmentary specimens". | A pycnodont. |
Cartilaginous fish
Cartilaginous fish of the Aguja Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Member | Material | Notes | Images |
Brachyrhyzodus[8] | B. wichitaensis | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "8 complete specimens". | ||
Cantioscyllium[8] | C. aff. meyeri | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 1 anterior tooth and 5 lateral teeth. | A nurse shark. | |
Chiloscyllium[8] | C. aff. greeni | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "Approximately 46 complete and fragmentary teeth". | ||
Chondrichthyes[8] | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 23 placoid scales and 69 dermal scales. | 4 morphotypes of placoid scales (A to D) present. | ||
Cretalamna[8] | C. appendiculata | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "3 fragmentary teeth". | ||
Cretorectolobus[8] | C. olsoni | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "20 complete and fragmentary teeth". | A carpet shark. | |
Hybodus[8] | H. sp. | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 2 specimens, one complete and one partial tooth. | A hybodont. | |
Igdabatis[8] | I. indicus? | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | A single incomplete tooth. | A myliobatid. | |
Ischyrhiza[8] | I. cf. avonicola | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "Five complete and fragmentary rostral teeth". | A sawskate. | |
I. mira | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "Seven fragmentary rostral teeth and approximately 216 whole and fragmentary oral teeth". | A sawskate. | ||
Lonchidion[8] | L. selachos | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 4 complete and 5 fragmentary teeth. | A hybodont. | |
Myliobatiformes[8] | Incertae sedis | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 3 complete specimens. | ||
Protoplatyrhina[8] | P. renae | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "63 complete and fragmentary teeth". | A hypsobatid. | |
Ptychotrygon[8] | P. agujaensis | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "Over 400 complete and fragmentary specimens". | A sawskate. | |
P. triangularis | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "Over 163 complete and fragmentary specimens". | A sawskate. | ||
P. aff. cuspidata | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "Seven whole and fragmentary specimens". | A sawskate. | ||
P. sp. | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "7 fragmentary teeth". | A sawskate. | ||
Rhinobatos[8] | R. casieri | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "14 complete and fragmentary specimens". | A guitarfish. | |
Rhombodus[8] | R. levis | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "15 complete and fragmentary specimens". | ||
Scapanorhynchus[8] | S. texanus | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "Approximately 165 complete and fragmentary anterior and lateral teeth, and 2 posterior teeth". | A mitsukurinid. | |
Sclerorhynchidae[8] | Morphotype 1 | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | One fragmentary specimen. | A sawskate. | |
Morphotype 2 | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | One fragmentary specimen. | A sawskate. | ||
Morphotype 3 | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 3 fragmentary rostral teeth. | A sawskate. | ||
Morphotype 4 | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 16 complete and fragmentary specimens. | A sawskate. | ||
Squalicorax[8] | S. kaupi | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "26 complete and fragmentary anterior and lateral teeth". | An anacoracid. | |
S. pristodontus | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | 2 specimens. | An anacoracid. | ||
Squatina[8] | S. hassei | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | A single complete specimen. | An angelshark. | |
Texatrygon[8] | T. hooveri | Ten Bits Ranch. | Rattlesnake Mountain sandstone member.[8] | "Four complete and fragmentary specimens". | A sawskate. |
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 |
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.
- ^ a b c 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. doi:10.1080/14772019.2019.1625078. ISSN 1477-2019. S2CID 202018197.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk bl bm bn bo bp bq br bs bt bu bv bw bx by bz ca cb cc cd ce cf cg ch Schubert, Joseph (May 2013). Elasmobranch and osteichthyan fauna of the Rattlesnake Mountain Sandstone, Aguja Formation (Upper Cretaceous; Campanian), West Texas (Thesis thesis).
- ^ a b c d e f g h i "Aguja Formation (Upper Shale Member), Big Bend Region, Texas," in Sullivan and Lucas (2006). Page 16.
- ^ "The first mandible fragment of Deinosuchus (Eusuchia: Alligatoroidea) discovered in Coahuila, Mexico". ResearchGate. Retrieved 2016-03-27.
- ^ a b c d e "Abstract," Lucas, Sullivan, and Hunt (2006)
- ^ a b Longrich, N. R.; Sankey, J.; Tanke, D. (2010). "Texacephale langstoni, a new genus of pachycephalosaurid (Dinosauria: Ornithischia) from the upper Campanian Aguja Formation, southern Texas, USA". Cretaceous Research. 31 (2): 274. doi:10.1016/j.cretres.2009.12.002.
- ^ Lehman, T.M.; Wick, S.L.; Barnes, K.R. (2016). "New specimens of horned dinosaurs from the Aguja Formation of West Texas, and a revision of Agujaceratops". Journal of Systematic Palaeontology. Online edition. doi:10.1080/14772019.2016.1210683.
- ^ a b c Wagner and Lehman (2009).
- ^ a b c "Dinosaur distribution (Texas and Chihuahua)." Weishampel, et al. (2004). Page 582 and 588.
- ^ a b c d e f g h i j k l "Dinosaur distribution (Late Cretaceous; North America; Texas)." Weishampel, et al. (2004). Page 582.
- ^ "Table 23.1," in Weishampel, et al. (2004). Page 496.
- ^ Listed as Edmontonia cf. rugosidens in "Dinosaur distribution (Late Cretaceous; North America; Texas).", Weishampel et al., 2004, p.582
- ^ a b c d e f g West, Bryanna (2020). Campanian-Maastrictian Ankylosaurs of West Texas (PDF) (Thesis). Texas Tech University.
- ^ Listed as ?Gryposaurus sp. in "Dinosaur distribution (Late Cretaceous; North America; Texas)." Weishampel, et al. (2004). Page 582.
- ^ Prieto-Márquez, A. (2013). "Skeletal morphology of Kritosaurus navajovius (Dinosauria:Hadrosauridae) from the Late Cretaceous of the North American south-west, with an evaluation of the phylogenetic systematics and biogeography of Kritosaurini." Journal of Systematic Palaeontology, (advance online publication) doi:10.1080/14772019.2013.770417
- ^ "Dinosaur distribution (Late Cretaceous; North America; Chihuahua)." Weishampel, et al. (2004). Page 588.
- ^ a b c "Abstract," Longrich, Sankey, and Tanke (2010).
- ^ Rivera-Sylva, H.E.; Hendrick, B.P.; Dodson, P. (2016). "A Centrosaurine (Dinosauria: Ceratopsia) from the Aguja Formation (Late Campanian) of Northern Coahuila, Mexico". PLOS ONE. 11 (4): e0150529. Bibcode:2016PLoSO..1150529R. doi:10.1371/journal.pone.0150529. PMC 4830452. PMID 27073969.
- ^ Rivera-Sylva, H.E.; Hendrick, B.P.; Dodson, P. (2016). "A Centrosaurine (Dinosauria: Ceratopsia) from the Aguja Formation (Late Campanian) of Northern Coahuila, Mexico". PLOS ONE. 11 (4): e0150529. Bibcode:2016PLoSO..1150529R. doi:10.1371/journal.pone.0150529. PMC 4830452. PMID 27073969.
- ^ Rivera-Sylva, H.E.; Frey, E.; Stinnesbeck, W.; Guzman-Gutirrez, J.R.; Gonzalez-Gonzalez (2017). "Mexican ceratopsids: Considerations on their diversity and evolution". Journal of South American Earth Sciences. doi:10.1016/j.jsames.2017.01.008.
- ^ Sullivan, R.M., and Lucas, S.G. 2006. "The Kirtlandian land-vertebrate "age" – faunal composition, temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America[permanent dead link]." New Mexico Museum of Natural History and Science, Bulletin 35:7-29.
- ^ a b c d Mortimer, M (2004). "Tyrannosauroidea". The Theropod Database. Archived from the original on 2013-09-29. Retrieved 2007-08-21.
- ^ a b Listed as cf. Dromaeosaurus sp. in "Dinosaur distribution (Late Cretaceous; North America; Texas)." Weishampel, et al. (2004). Page 582.
- ^ Longrich, N. R.; Barnes, K.; Clark, S.; Millar, L. (2013). "Caenagnathidae from the Upper Campanian Aguja Formation of West Texas, and a Revision of the Caenagnathinae". Bulletin of the Peabody Museum of Natural History 54: 23. doi:10.3374/014.054.0102. edit
- ^ a b c d "Dinosaur distribution (Late Cretaceous; North America; Texas)." Weishampel, et al. (2004). Page 581.
- ^ Listed as R. cf. gilmorei in "Dinosaur distribution (Late Cretaceous; North America; Texas)." Weishampel, et al. (2004). Page 581.
- ^ Listed as Saurornitholestes cf. langstoni in "Dinosaur distribution (Late Cretaceous; North America; Texas)." Weishampel, et al. (2004). Page 582.
- ^ a b Listed as cf. Troodon sp. in "Dinosaur distribution (Late Cretaceous; North America; Texas)." Weishampel, et al. (2004). Page 582.
- ^ a b c d e f Wick, Steven L. (2021-12-01). "New early Campanian characiform fishes (Otophysi: Characiformes) from West Texas support a South American origin for known Late Cretaceous characiforms from North America". Cretaceous Research. 128: 104993. doi:10.1016/j.cretres.2021.104993. ISSN 0195-6671.
Bibliography
- Lehman, Thomas M.; Susan L. Tomlinson (2004). "Terlinguachelys fischbecki, a new genus and species of sea turtle (Chelonioidea: Protostegidae) from the Upper Cretaceous of Texas". Journal of Paleontology. The Paleontological Society. 78 (6): 1163–1178. doi:10.1666/0022-3360(2004)078<1163:TFANGA>2.0.CO;2.
- Longrich, N.R., Sankey, J., and Tanke, D. (2010) Texacephale langstoni, a new genus of pachycephalosaurid (Dinosauria: Ornithischia) from the upper Campanian Aguja Formation, southern Texas, USA. Cretaceous Research. doi:10.1016/j.cretres.2009.12.002.
- Sullivan, R.M., and Lucas, S.G. 2006. "The Kirtlandian land-vertebrate "age" – faunal composition, temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America[permanent dead link]." New Mexico Museum of Natural History and Science, Bulletin 35:7-29.
- Spencer G. Lucas, Robert M. Sullivan and Adrian P. Hunt: Re-evaluation of Pentaceratops and Chasmosaurus (Ornithischia: Ceratopsidae) in the Upper Cretaceous of the Western Interior. In: New Mexico Museum of Natural History and Science Bulletin 35 (2006), S. 367-370.PDF[permanent dead link]
- Wagner, Jonathan R.; Lehman, Thomas M. (2009). "An Enigmatic New Lambeosaurine Hadrosaur (Reptilia: Dinosauria) from the Upper Shale Member of the Campanian Aguja Formation of Trans-Pecos Texas". Journal of Vertebrate Paleontology. 29 (2): 605–611. doi:10.1671/039.029.0208. S2CID 128555861.
- The Dinosauria, 2nd edition, 1–880. Berkeley: University of California Press. Accessed 2019-02-21. ISBN 0-520-24209-2 ; , and . 2004.
- All articles with dead external links
- Articles with dead external links from May 2017
- Articles with permanently dead external links
- Coordinates not on Wikidata
- Articles with dead external links from October 2018
- Geologic formations of Texas
- Cretaceous geology of Texas
- Geologic formations of Mexico
- Cretaceous Mexico
- Campanian Stage
- Sandstone formations
- Conglomerate formations
- Shale formations
- Deltaic deposits
- Lacustrine deposits
- Tidal deposits
- Paleontology in Mexico
- Paleontology in Texas
- Geography of Chihuahua (state)
- Geography of Coahuila