Gryposuchus

Last updated

Gryposuchus
Temporal range: Miocene,
16–5.3  Ma [1]
Gryposuchus colombianus skull.jpg
Fossils of the skull and mandible of G. colombianus, Museo Geológico José Royo y Gómez, Bogotá.
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Crocodilia
Family: Gavialidae
Subfamily:† Gryposuchinae
Genus:† Gryposuchus
Gurich, 1912
Type species
†Gryposuchus jessei
Gurich, 1912
Other species
  • †G. neogaeus
    (Burmeister, 1885 [originally Rhamphostomopsis neogaeus])
  • †G. colombianus
    Langston, 1965
  • †G. croizati
    Riff & Aguilera, 2008
  • †G. pachakamue
    Salas-Gismondi et al., 2016

Gryposuchus is an extinct genus of gavialid crocodilian. Fossils have been found from Argentina, Colombia, Venezuela, Brazil and the Peruvian Amazon. The genus existed during the Miocene epoch (Colhuehuapian to Huayquerian). [2] One recently described species, G. croizati, grew to an estimated length of 10 metres (33 ft). Gryposuchus is the type genus of the subfamily Gryposuchinae, although a 2018 study indicates that Gryposuchinae and Gryposuchus might be paraphyletic and rather an evolutionary grade towards the gharial.

Contents

Species

The type species of Gryposuchus is G. jessei, named based on a well-preserved rostrum collected along the Pauini River of Brazil in 1912. The specimen was probably destroyed during World War II by the 1943 bombing of Hamburg. [3] Another specimen named UFAC 1272, consisting of a premaxilla and maxilla, was discovered in the nearby Sena Madureia locality of the late Miocene Solimões Formation, [2] in and referred to the species in 1997. [4] G. jessei is also referred to from the Urumaco Formation of northwestern Venezuela. [2] A second species, G. neogaeus, was referred to the genus in 1982; specimens from this species were first described from the late Miocene Ituzaingó Formation of Argentina in 1885, [2] [5] although it was referred to Rhamphostomopsis at the time. [3] [6] [7]

Another species, G. colombianus, has been recovered from deposits from the Middle Miocene Honda Group of Colombia, and the late Miocene Urumaco Formation in Venezuela. [2] This species, named in 1965, was originally referred to Gavialis . [8] Fragmentary material of Gryposuchus from the Fitzcarrald Arch in the Peruvian Amazon dating back to the late middle Miocene bear a close resemblance to G. colombianus, but differ in rostrum proportions. [2] [9] G. neogaeus and G. colombianus have been proposed as synonyms of G. jessei, [10] but this is unlikely due to the number of anatomical differences between them. [3] [4]

Scale diagram showing the size of G. croizati (light blue) Large crocodyliformes.svg
Scale diagram showing the size of G. croizati (light blue)
South America laea relief location map.jpg
Yellow ffff80 pog.svg
Yellow ffff80 pog.svg
Gold pog.svg
Orange ff8040 pog.svg
Yellow pog.svg
class=notpageimage|
Gryposuchus fossil localities
Orange ff8040 pog.svg Colloncuran
Gold pog.svg Laventan
Yellow pog.svg Chasicoan
Yellow ffff80 pog.svg Huayquerian

A species described in 2008, G. croizati, also found from the upper Miocene Urumaco Formation in Venezuela, [2] can be distinguished from other species of Gryposuchus on the basis of a reduced number of maxillary teeth, a slender parietal interfenestral bar, and widely separated and reduced palatine fenestrae, and other characters. Based on measurements of the orbital cranial skeleton, the length of the animal has been estimated at around 10.15 metres (33.3 ft) in length, with a total mass of about 1,745 kilograms (3,847 lb). Measuring the entire length of the skull from the end of the rostrum to the supraoccipital would result in a much larger size estimate, up to three times as great. However, because there is considerable variation seen in rostral proportions among crocodilians, the latter measurements are probably not an accurate way of estimating body mass and length. [11] Despite this, the species is still one of the largest crocodilians known to have existed, and it may indeed have been the largest gavialoid to have ever existed if a recent revision in the estimated size of the large tomistomine Rhamphosuchus is correct (the genus was once considered to be 15 metres (49 ft) in length; the new estimate puts it at approximately 10 metres (33 ft)). [12]

Some skull material also recovered from Peruvian Amazon (Iquitos) in the Pebas Formation of the Middle Miocene, [2] was named as Gryposuchus pachakamue in 2016 by Rodolfo Salas-Gismondi et al. It includes the holotype MUSM 987, a well preserved skull that lacks of temporal and occipital bones; it measures 623.2 millimeters in length, and a series of referred specimens, including possible juveniles. The species was named after the Quechuan word for a primordial god and "storyteller". [13] This new species is characterized by have 22 teeth in the mandible and the maxilla, a snout comparable in relative length to the modern Gavialis gangeticus , and is notable since that its orbits were wider than long and not so upturned as another species of gavialids, including the gryposuchines, which implies that G. pachakamue doesn't had the "telescoped" orbits (protruding eyes) condition fully developed. Since that it species, that inhabited the proto-Amazon fluvial system 13 million years ago, is the oldest record of gavialids in this area and it had a primitive telescoped eyes condition, it shows that the development of such condition was a case of convergent evolution with the species of Gavialis also found in fluvial environments. [13]

Indeterminate finds of Gryposuchus were noted from the early Miocene Castillo Formation of Venezuela, middle Miocene Pebas Formation of Peru, middle/late Miocene Tranquitas Formation of Argentina and from the late Miocene formations Urumaco of Venezuela and Solimões in both Brazil and Peru. [2] Additionally, indeterminate finds of gavialoids (all in either coastal or marine sediments) are present in the early Miocene Jimol Formation and the early/middle Miocene Castilletes Formation in Colombia, [2] [14] and from the Oligo-Miocene boundary Pirabas Formation of coastal Brazil. [15]

Phylogeny

A phylogenetic analysis conducted in a 2007 study found Gryposuchinae to include the genera Aktiogavialis , Gryposuchus, Ikanogavialis , Piscogavialis , and Siquisiquesuchus . Below is a cladogram from the 2007 analysis showing the phylogenetic relationships of gryposuchines among gavialoids: [16]

Gavialoidea  

Eothoracosaurus

Thoracosaurus

Eosuchus

Argochampsa

Gavialidae  

Eogavialis

Gavialis

Gryposuchinae  

Ikanogavialis

Piscogavialis

Siquisiquesuchus

Gryposuchus

Aktiogavialis

Alternatively, a 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data indicated that the members of Gryposuchinae and the genus Gryposuchus may in fact be paraphyletic and rather an evolutionary grade towards Gavialis and the gharial, as shown in the cladogram below: [17]

Gavialidae

Gavialis gangeticus Gharial

Gavialis bengawanicus †

Gavialis browni †

Gryposuchus colombianus †

Ikanogavialis †

Gryposuchus pachakamue †

Piscogavialis †

Harpacochampsa †

Toyotamaphimeia †

Penghusuchus †

Gavialosuchus †

Tomistoma lusitanicum †

Tomistoma schlegelii False gharial

Gryposuchinae

Paleoecology

The Miocene epoch represents the only history of gavialoids (solely of the subfamily Gryposuchinae ) in South America, from a Caribbean launchpad ( Aktiogavialis from the Middle Oligocene of Puerto Rico, [16] and Dadagavialis from the Early Miocene of Panama). [18] Although there were six other confirmed genera of gryposuchine, Gryposuchus was almost certainly the most successful, with an existence potentially encompassing almost all of the Miocene, and a range from Venezuela to Argentina in the Middle to Late Miocene. This dominance was likely due to the fact that Gryposuchus was one of only two freshwater adapted gryposuchines (other than Hesperogavialis ), [19] whereas the others (such as Siquisiquesuchus and Piscogavialis ) were either primarily estuarine, coastal or marine based predators. [20] [21] This would certainly have been useful in taking advantage of the extensive continental waterways and swamps of what would become the Amazon basin. Gryposuchus can be observed far and wide, from coastally adjacent and inclusive formations, such as the Urumaco Formation of Venezuela, [22] [23] to even beyond the northern drainage basins, into Argentina. [5] This is in contrast with almost all the other species within the subfamily, which are limited to certain time periods near or on coast, with only Hesperogavialis penetrating into Brazil in the Late Miocene.

Although Gryposuchus had already reached Argentina by the Middle Miocene, [2] known species diversity reached its peak by the Late Miocene, with four of the five species present, three of which were also overlapping in the Urumaco Formation. Gryposuchinae diversity also reached its peak, at five genera across South America. However, at the Miocene/Pliocene boundary, all Gavialoidea and Crocodyloidea (another superfamily colonising in the Miocene) were likely extirpated from South America, with the endemic Caimaninae undergoing a severe reduction in size and diversity as well. This was likely due to the continuing elevation of the northern sections of the Andes chain creating the future Amazon basin, re-rerouting drainage flowing towards the Caribbean to the much cooler Atlantic, and transforming the mega-wetlands responsible for the hyper-diversity of crocodilians into a fully developed riverine drainage system. The co-current aridification of the continental interior, and filling of peripheral wetland basins, further restricted the space and food resources of these large, food-intensive specialist crocodilians, and was probably the primary cause of their extinction. [2] [14] [24]

Related Research Articles

<span class="mw-page-title-main">Gavialinae</span> Subfamily of gharial crocodylians

Gavialinae is a subfamily of large semiaquatic crocodilian reptiles, resembling crocodiles, but with much thinner snouts. Gavialinae is one of the two major subfamilies within the family Gavialidae - the other being the subfamily Tomistominae, which contains the false gharial and extinct relatives.

<span class="mw-page-title-main">Gavialidae</span> Family of gharial crocodylians

Gavialidae is a family of large semiaquatic crocodilians with elongated, narrow snouts. Gavialidae consists of two living species, the gharial and the false gharial, both occurring in Asia. Many extinct members are known from a broader range, including the recently extinct Hanyusuchus. Gavialids are generally regarded as lacking the jaw strength to capture the large mammalian prey favoured by crocodiles and alligators of similar size so their thin snout is best used to catch fish, however the false gharial has been found to have a generalist diet with mature adults preying upon larger vertebrates, such as ungulates.

<i>Purussaurus</i> Extinct genus of reptiles

Purussaurus is an extinct genus of giant caiman that lived in South America during the Miocene epoch, from the Friasian to the Huayquerian in the SALMA classification. It is known from skull material found in the Brazilian and Peruvian Amazon, Colombian Villavieja Formation, Panamanian Culebra Formation, Urumaco and Socorro Formations of northern Venezuela.

<i>Mourasuchus</i> Extinct genus of reptiles

Mourasuchus is an extinct genus of giant, aberrant caiman from the Miocene of South America. Its skull has been described as duck-like, being broad, flat, and very elongate, superficially resembling Stomatosuchus from the Late Cretaceous.

<i>Aktiogavialis</i> Species of reptile (fossil)

Aktiogavialis is an extinct genus of crocodylian that lived from the Oligocene until the Miocene in what is now the Caribbean. Two species have been described: Aktiogavialis puertoricensis from the Middle Oligocene of Puerto Rico and Aktiogavialis caribesi from the Huayquerian of the Late Miocene of Venezuela.

Eogavialis is an extinct genus of eusuchian crocodylomorph, usually regarded as a gavialoid crocodylian. It superficially resembles Tomistoma schlegelii, the extant false gharial, and consequently material from the genus was originally referred to Tomistoma. Indeed, it was not until 1982 that the name Eogavialis was constructed after it was realised that the specimens were from a more basal form.

<i>Eothoracosaurus</i> Extinct genus of reptiles

Eothoracosaurus is an extinct monospecific genus of eusuchian crocodylomorphs found in Eastern United States which existed during the Late Cretaceous period. Eothoracosaurus is considered to belong to an informally named clade called the "thoracosaurs", named after the closely related Thoracosaurus. Thoracosaurs in general were traditionally thought to be related to the modern false gharial, largely because the nasal bones contact the premaxillae, but phylogenetic work starting in the 1990s instead supported affinities within gavialoid exclusive of such forms. Even more recent phylogenetic studies suggest that thoracosaurs might instead be non-crocodilian eusuchians.

Hesperogavialis is an extinct genus of gryposuchine gavialid. Fossils have been found from Venezuela and Brazil that date back to the Middle to Late Miocene. Although Hesperogavialis is one of the best known gavialoids from South America, the posterior portion of the skull is still unknown, making any attempts at classification within the family somewhat more difficult than other gavialoids in which much of the skull is present. The genus possibly comprises three species. The type species, H. cruxenti, has been found in the Urumaco Formation in Venezuela. A second possible species, named H. bocquentini, has been described from the Solimões Formation in Acre, Brazil, and can be distinguished from H. cruxenti by the asymmetry seen in the anterior portion of the nasals and the small distance between alveoli. A third species can be recognized from the same locality in Acre, although a formal name has yet to be given to it.

Ikanogavialis is an extinct genus of gavialid crocodilian. Fossils have been found in the Urumaco Formation in Urumaco, Venezuela and the Solimões Formation of Brazil. The strata from which remains are found are late Miocene in age, rather than Pliocene as was once thought. A possible member of this genus survived into the Late Holocene on Muyua or Woodlark Island in Papua New Guinea.

<i>Piscogavialis</i> Extinct genus of reptiles

Piscogavialis is an extinct monospecific genus of gryposuchine gavialid crocodylian. The only species yet known is P. jugaliperforatus. Fossils of Piscogavialis have been found from the Mio-Pliocene Pisco Formation of the Sacaco Basin in southern Peru in 1998, where it coexisted with the much smaller gavialid Sacacosuchus.

Siquisiquesuchus is an extinct genus of gavialid crocodilian. It is known from cranial remains and a few postcranial bones found in Miocene-age rocks of the Castillo Formation in northwestern Venezuela.

<i>Penghusuchus</i> Extinct genus of reptiles

Penghusuchus is an extinct genus of gavialid crocodylian. It is known from a skeleton found in Middle to Upper Miocene rocks of Penghu Island, off Taiwan. The taxon was described in 2009 by Shan and colleagues; the type species is P. pani. It may be related to two other fossil Asian gavialids: Toyotamaphimeia machikanensis of Japan and Hanyusuchus sinensis of South China. It was a medium-sized gavialid with an estimated total length of 4.5 metres (15 ft).

Gryposuchinae is an extinct subfamily of gavialid crocodylians. Gryposuchines lived mainly in the Miocene of South America. However, "Ikanogavialis" papuensis may have survived more recently, into the Late Pleistocene/Holocene. Most were long-snouted coastal forms. The group was named in 2007 and includes genera such as Gryposuchus and Aktiogavialis, although a 2018 study indicates that the group might be paraphyletic and rather an evolutionary grade towards the gharial.

<span class="mw-page-title-main">Tomistominae</span> Subfamily of reptiles

Tomistominae is a subfamily of crocodylians that includes one living species, the false gharial. Many more extinct species are known, extending the range of the subfamily back to the Eocene epoch. In contrast to the false gharial, which is a freshwater species that lives only in southeast Asia, extinct tomistomines had a global distribution and lived in estuaries and along coastlines.

Globidentosuchus is an extinct genus of basal caimanine crocodylian known from the late Middle to Late Miocene of the Middle and the Upper Members of the Urumaco Formation at Urumaco, Venezuela. Its skull was very short and robust, with large units of spherical teeth used to break the shells of molluscs as part of its durophagus diet. It is thought to be one of the most basal Caimanines, even sharing some traits with alligatorids.

<i>Caiman wannlangstoni</i> Extinct species of reptile

Caiman wannlangstoni is an extinct species of caiman that lived in what is now the Amazon Basin and surrounding areas during the Middle and Late Miocene. Fossils of C. wannlangstoni have been found in the Pebas Formation near Iquitos in Peru and include partial skulls and isolated skull bones. Other fossils were uncovered from the Urumaco Formation in Venezuela and the Laventan Honda Group of Colombia. The species was first described in 2015. Features that in combination distinguish C. wannlangstoni from other caimans include a deep snout, a wavy upper jaw margin, a large and upward-directed narial opening, and blunt teeth at the back of the jaws. Based on the sizes of the skulls, its estimated body length is about 211 to 227 centimetres.

Tomistoma cairense is an extinct species of gavialoid crocodilian from the Lutetian stage of the Eocene era. It lived in North East Africa, especially Egypt. Remains of T. cairense have been found in the Mokattam Formation, in Mokattam, Egypt. Tomistoma cairense did not have a Maxilla process within their lacrimal gland, whereas all extant (living) crocodilians do.

The Urumaco Formation is a formation in Venezuela that includes deposits from the Late Miocene. It is the site of several "giant forms": the turtles, crocodiles, sloths and rodents of Urumaco are among the largest of their groups.

Caiman brevirostris is an extinct species of caiman that lived during the Late Miocene, around 11.6 million years ago, to the end of the Miocene 5.3 million years ago in Acre and Amazonas, Brazil as well as Urumaco, Venezuela. Several specimens have been referred to the species, but only 3 of them are confidently placed in the species. C. brevirostris was originally named in 1987 on the basis of a single, incomplete rostrum with an associated mandibular ramus that had been found in Acre, Brazil. C. brevirostris is very distinct among Caiman species and caimaninae overall in that it preserves a characteristically short and robust skull that bears blunt posterior teeth that were built to break down harder foods. This was an adaption for durophagy, likely to crush shells of mollusks and clams which were common in the wetlands that C. brevirostris resided in.


Sacacosuchus is an extinct monospecific genus of marine gavialid that lived along the coast of the south-east Pacific from approximately 19 to 6.3 million years ago. Its fossils have been found in the Chilcatay and Pisco Formations of Peru, where it coexisted with the much larger Piscogavialis. Based on its skull, Sacacosuchus was most likely a generalist feeder with an estimated total body length of 4.32 m (14.2 ft). Its extinction is thought to have been caused by a combination of factors including falling sea levels and global cooling.

References

  1. ↑ Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ . 9: e12094. doi: 10.7717/peerj.12094 . PMC   8428266 . PMID   34567843.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 Cidade, Giovanne; Fortier, Daniel; Hsiou, Annie (2018-12-01). "The crocodylomorph fauna of the cenozoic of South America and its evolutionary history: A review". Journal of South American Earth Sciences. 90: 392–411. doi:10.1016/j.jsames.2018.12.026. S2CID   134902094.
  3. 1 2 3 de Souza, R.G.; Riff, D.; de Souza-Filho, J.P.; Kellner, A.W.A. (2018). "Revisiting Gryposuchus jessei Gürich, 1912 (Crocodylia: Gavialoidea): specimen description and comments on the genus". Zootaxa. 4457 (1): 167–178. doi:10.11646/zootaxa.4457.1.9. PMID   30314186. S2CID   52976475.
  4. 1 2 Langston, W.; Gasparini, Z. (1997). "Crocodilians, Gryposuchus, and the South Americans gavials". In Kay, R.F.; Madden, R.H.; Cifelli, R.L.; Flynn, J.J. (eds.). Vertebrate Paleontology in the Neotropics: The Miocene Fauna of La Venta, Colombia. Washington: Smithsonian Institution. pp. 113–154.
  5. 1 2 Bona, Paula; Riff, Douglas; Gasparini, Zulma (2013-09-23). "Late Miocene crocodylians from northeast Argentina: New approaches about the austral components of the Neogene South American crocodylian fauna". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 29 (3–4): 551–570. doi:10.1017/S175569101300042X. S2CID   131646050.
  6. ↑ Burmeister, G. (1885). "Examen crítico de los mamíferos y los reptiles denominados pot Don Augusto Bravard". Anales del Museo Púbtico de Buenos Aires. 3: 95–173.
  7. ↑ Cozzuol, M. A. (2006). "The Acre vertebrate fauna: Age, diversity, and geography". Journal of South American Earth Sciences. 21 (3): 185–203. Bibcode:2006JSAES..21..185C. doi:10.1016/j.jsames.2006.03.005.
  8. ↑ Langston, W. (1965). "Fossil crocodilians from Colombia and the Cenozoic history of the Crocodilia in South America". University of California Publications in Geological Sciences. 52: 1–152.
  9. ↑ Salas-Gismondi, R.; Antoine, P. O.; Baby, P.; Brusset, S.; Benammi, M.; Espurt, N.; de Franceschi, D.; Pujos, F.; Tejada, J.; Urbina, M (2007). "Middle Miocene crocodiles from the Fitzcarrald Arch, Amazonian Peru". In Díaz-Martínez, E.; Rábano, I. (eds.). 4th European Meeting on the Palaeontology and Stratigraphy of Latin America. Cuadernos del Museo Geominero. Vol. 8. Madrid: Instituto Geológico y Minero de España.
  10. ↑ Buffetaut, E. (1982). "Systematique, origine et évolution des Gavialidae Sud Américains". Geobios. 16 (1S): 127–140. doi:10.1016/S0016-6995(82)80107-1.
  11. ↑ Riff, D.; Aguilera, O. A. (2008). "The world's largest gharials Gryposuchus: description of G. croizati n. sp. (Crocodylia, Gavialidae) from the Upper Miocene Urumaco Formation, Venezuela". Paläontologische Zeitschrift. 82 (2): 178–195. doi:10.1007/bf02988408. S2CID   85172486.
  12. ↑ Head, J. J. (2001). "Systematics and body size of the gigantic, enigmatic crocodyloid Rhamphosuchus crassidens, and the faunal history of Siwalik Group (Miocene) crocodylians". Journal of Vertebrate Paleontology. 21 (Supplement to No. 3): 59A.
  13. 1 2 Salas-Gismondi, Rodolfo; Flynn, John J.; Baby, Patrice; Tejada-Lara, Julia V.; Claude, Julien; Antoine, Pierre-Olivier (2016). "A New 13 Million Year Old Gavialoid Crocodylian from Proto-Amazonian Mega-Wetlands Reveals Parallel Evolutionary Trends in Skull Shape Linked to Longirostry". PLOS ONE. 11 (4): e0152453. Bibcode:2016PLoSO..1152453S. doi: 10.1371/journal.pone.0152453 . PMC   4838223 . PMID   27097031.
  14. 1 2 Moreno-Bernal, Jorge W.; Head, Jason; Jaramillo, Carlos A. (2016-05-03). "Fossil Crocodilians from the High Guajira Peninsula of Colombia: Neogene faunal change in northernmost South America". Journal of Vertebrate Paleontology. 36 (3): e1110586. doi:10.1080/02724634.2016.1110586. ISSN   0272-4634. S2CID   130332367.
  15. ↑ Moraes-Santos, Heloisa; Villanueva, Jean Bocquentin; Toledo, Peter Mann (2011-12-01). "New remains of a gavialoid crocodilian from the late Oligocene−early Miocene of the Pirabas Formation, Brazil". Zoological Journal of the Linnean Society. 163 (suppl_1): S132–S139. doi: 10.1111/j.1096-3642.2011.00710.x . ISSN   0024-4082.
  16. 1 2 Vélez-Juarbe, Jorge; Brochu, C.A.; Santos, H. (2007). "A gharial from the Oligocene of Puerto Rico: transoceanic dispersal in the history of a non-marine reptile". Proceedings of the Royal Society B. 274 (1615): 1245–1254. doi:10.1098/rspb.2006.0455. PMC   2176176 . PMID   17341454.
  17. ↑ Michael S. Y. Lee; Adam M. Yates (27 June 2018). "Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil". Proceedings of the Royal Society B . 285 (1881). doi: 10.1098/rspb.2018.1071 . PMC   6030529 . PMID   30051855.
  18. ↑ Salas-Gismondi, Rodolfo; Moreno-Bernal, Jorge W.; Scheyer, Torsten M.; Sánchez-Villagra, Marcelo R.; Jaramillo, Carlos (2019-06-18). "New Miocene Caribbean gavialoids and patterns of longirostry in crocodylians". Journal of Systematic Palaeontology. 17 (12): 1049–1075. doi:10.1080/14772019.2018.1495275. ISSN   1477-2019. S2CID   91495532.
  19. ↑ Kay, R. F. and Madden, R. H. (1997). Paleogeography and paleoecology. In: Kay, R. F., Madden, R. H, Cifelli, R. L., and Flynn, J. J., eds., Vertebrate paleontology in the neotropics: the Miocene fauna of La Venta, Colombia. Smithsonian Institution Press; Washington, DC. pp. 520–550.
  20. ↑ Kraus, R (1998). "The cranium of Piscogavialis jugaliperforatus n. gen., n. sp. (Gavialidae, Crocodylia) from the Miocene of Peru". Paläontologische Zeitschrift. 72 (3–4): 389–406. doi:10.1007/bf02988368. S2CID   84214781.
  21. ↑ Brochu, C. A.; Rincon, A. D. (2004). "A gavialoid crocodylian from the Lower Miocene of Venezuela". Special Papers in Palaeontology. 71: 61–78.
  22. ↑ Linares, O. J. (2004). "Bioestratigrafia de la fauna de mamiferos de las Formaciones Socorro, Urumaco y Codore (Mioceno Medio–Plioceno Temprano) de la region de Urumaco, Falcon, Venezuela". Paleobiologia Neotropical. 1: 1–26.
  23. ↑ Sánchez-Villagra, M. R.; Aguilera, O. A. (2006). "Neogene vertebrates from Urumaco, Falcón State, Venezuela: diversity and significance". Journal of Systematic Palaeontology. 4 (3): 213–220. doi:10.1017/s1477201906001829. S2CID   84357359.
  24. ↑ "Fourteen closely related crocodiles existed around 5 million years ago". ScienceDaily. Retrieved 2020-04-19.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.