Morelet's crocodile

Last updated

Morelet's crocodile
Temporal range: Late Pleistocene–Present, 0.1–0  Ma [1]
Ꞓ
O
S
D
C
P
T
J
K
Pg
N
↓
Crocodile de Morelet.jpeg
CITES Appendix I
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauria
Order: Crocodilia
Superfamily: Crocodyloidea
Family: Crocodylidae
Genus: Crocodylus
Species:
C. moreletii
Binomial name
Crocodylus moreletii
The range of Morelet's crocodile.png
Range of Crocodylus moreletii
Synonyms [3]
  • Crocodilus moreletii
    A.H.A. Duméril & Bibron, 1851
  • Crocodilus americanus var. moreletii
    A.H.A. Duméril & Bibron, 1851
  • Alligator lacordairei
    Preudhomme de Borre, 1869
  • Crocodylus mexicanus
    Bocourt, 1869

Morelet's crocodile (Crocodylus moreletii), also known commonly as the Mexican crocodile, the Belize crocodile, and el cocodrilo de pantano in Spanish, is a modest-sized crocodilian in the family Crocodylidae. The species is found only in the Atlantic regions of Mexico, Belize and Guatemala. [2] [4] It usually grows to about 3 metres (10 ft) in total length (tail included). It is a species at least concern for extinction according to the International Union for Conservation of Nature. [2] The species has a fossil record in Guatemala. [5]

Contents

Taxonomy and etymology

Morelet's crocodile was first discovered in 1850 in Mexico by the French naturalist Pierre Marie Arthur Morelet. The species was subsequently named after him in 1851 by French herpetologists Auguste Duméril and Gabriel Bibron. [6] [7] It was long confused with the American and Cuban crocodiles because of similar characteristics and an ambiguous type locality. It was not generally accepted as a separate species until the 1920s.

Evolution

The genus Crocodylus likely originated in Africa and radiated outwards towards Southeast Asia and the Americas, [8] although an Australia/Asia origin has also been considered. [9] Phylogenetic evidence supports Crocodylus diverging from its closest recent relative, the extinct Voay of Madagascar, around 25 million years ago, near the Oligocene/Miocene boundary. [8]

Phylogeny

Below is a cladogram based on a 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data, [10] as revised by the 2021 Hekkala et al. paleogenomics study using DNA extracted from the extinct Voay . [8] Hall's New Guinea crocodile placement suggested in 2023 study by Sales-Oliveira et al. [11]

Crocodylus

Crocodylus johnstoni Freshwater crocodile

Crocodylus novaeguineae New Guinea crocodile

Crocodylus halli Hall's New Guinea crocodile

Crocodylus mindorensis Philippine crocodile

Crocodylus porosus Saltwater crocodile

Crocodylus siamensis Siamese crocodile

Crocodylus palustris Mugger crocodile

Indo-Pacific

Crocodylus suchus West African crocodile

Africa

Crocodylus niloticus Nile crocodile

Crocodylus rhombifer Cuban crocodile

Latin America

Crocodylus intermedius Orinoco crocodile

Crocodylus acutus American crocodile

Crocodylus moreletii Morelet's crocodile

Characteristics

at Lago Coba, Quintana Roo, Mexico Morelets Crocodile.jpg
at Lago Cobá, Quintana Roo, Mexico
at Schonbrunn Zoo, Vienna Belize Crocodile.jpg
at Schönbrunn Zoo, Vienna

Morelet's crocodile (Crocoylus moreletii) is similar in appearance and morphology to the Cuban crocodile (Crocodylus rhombifer) and the larger American crocodile (Crocodylus acutus). When fully mature, Morelet's crocodile has a broad snout with 66–68 teeth. It is grayish-brown in color with dark bands and spots on the body and tail. This is similar to other crocodiles, like the American crocodile, but Morelet's crocodile is somewhat darker. Juvenile Morelet's crocodiles are bright yellow with dark bands. The iris is silvery brown. It has four short legs, giving it a rather sprawling gait, and a long tail, which is used for swimming. The hind feet are webbed. Despite its short legs, it is a fast runner. [6]

Morelet's crocodile is smaller than most other crocodiles, though it is larger than the dwarf crocodile (Osteolaemus tetraspis). Adult males are typically larger than females. The average adult Morelet's crocodile is about 2.1 m (6 ft 11 in) in total length (tail included), with a typical length range of 1.5 to 2.7 m (4 ft 11 in to 8 ft 10 in) (the lower measurement representing the mean total length of a female at sexual maturity which is attained at roughly 7–8 years of age in the wild). [12] [13] Almost all Morelet's crocodiles in excess of 2.5 m (8 ft 2 in) are males, and at this advanced stage of maturity, the male goes through a significant change in skull osteological morphology as the skull appears to increase in broadness and robustness. [14] Large adult males can attain a length of 3 m (10 ft), anything in excess of this is considered exceptionally rare for this species, however the species has a maximum reported length of 4.5 m (15 ft), with two other outsized specimens reportedly measuring 4.1 and 4.3 m (13 and 14 ft), respectively. [13] [15] [16] One mature adult specimen measuring 2.84 m (9 ft 4 in) and weighing 110 kg (240 lb) had a bite force of 4,399  N (989  lbf ). [17] The weight of a large 3 m (10 ft) wild male crocodile is estimated to average around 150 kg (330+3⁄4 lb), although mass is likely much more in outsized individuals. [13] [18] One large male with a presumed total length of around 3.5 m (11 ft 6 in) weighed about 250 kg (550 lb). [19] Another large individual measuring 3.3 m (10 ft 10 in) in length weighed 180 kg (400 lb). [20]

Distribution and habitat

Morelet's crocodile swimming 2017-08-19 AT Wien 13 Hietzing, Tiergarten Schonbrunn, Crocodylus moreletii (48090484156).jpg
Morelet's crocodile swimming

Morelet's crocodile can be found in freshwater habitats in Central America and along the Gulf of Mexico stretching through Belize, Guatemala, and Mexico. [21] The Belizean pine forests are an example of the type of ecoregion in which it occurs. [22]

In its freshwater habitats, it prefers isolated areas that are secluded. This species of crocodile can mainly be found in freshwater swamps and marshes which are located inland, and in large rivers and lakes. [23] Both of these habitats are forested to help add cover. [6]

Morelet's crocodile can also be found along the coast in brackish waters [2] and the grassy savannas on the Yucatán Peninsula. [24] It becomes much more distributed during the rainy seasons when flooding occurs and it is easier for it to move elsewhere. [24]

Juvenile Morelet's crocodiles live in very dense cover to protect themselves from other predators that might be in the area, and will remain there until they become older and able to fend for themselves. Adult crocodiles are known to dig out burrows during dry seasons in their area. [6] The range of Morelet's crocodile can overlap with that of the American crocodile, which can sometimes lead to them being confused with one another. Morelet's crocodile generally prefers mainland freshwater habitats, while the American crocodile in the shared range is typically found in areas of saline mangrove, often on cays or atolls. [2] Hybridization between the two species has been reported in Mexico and coastal Belize. [2]

Recently, Morelet's crocodile has been introduced into the Rio Grande (called Río Bravo in Mexico). [25] Several newspaper outlets on the Mexican side of the border report of reptiles inhabiting the river appearing not to be the American alligator which is native to Texas, but the Morelet's crocodile which is native to Tamaulipas from San Fernando southward. [26] [27] Crocodiles have been seen in the cities of Matamoros, [28] [29] [30] Reynosa [31] [32] [33] [34] [35] [36] and as far north as Nuevo Laredo. [37] [38] The sightings have prompted several municipal police departments to put up signs warning people about entering the river. [39]

Biology and behavior

Morelet's crocodile waiting for an ambush Morelet's Crocodile.jpg
Morelet's crocodile waiting for an ambush

Hunting and diet

Like most crocodilians, Morelet's crocodile is highly opportunistic and will prey on practically anything that it can overpower that comes into its territories. [40] Juvenile Morelet's crocodiles feed largely on fish and insects until they become bigger and more capable of bringing down larger prey. [23] Adults largely prey on small mammals, birds, other reptiles and fish, as well as gastropods, crustaceans and other invertebrates. [16] [40] [41] Dogs and goats have been taken by this species, including a record of a 2.9 m (9 ft 6 in) adult killing an English sheepdog which weighed at least 35 kg (77 lb). [42] Adults have also been recorded eating even larger animals, including cattle and tapirs, although these have been cases of scavenging on carcasses, with the tapir having been killed by a jaguar. [43] Morelet's crocodile has been known to be cannibalistic towards smaller specimens. The species has attacked humans on multiple occasions and at least 12 documented human fatalities have occurred. [44] Despite the relatively small size of the species, large adult Morelet's crocodiles are capable of overpowering a human. Due to partial consumption, recorded fatal attacks are likely predatory rather than defensive in nature. [19] [45] [46] The only natural predator of Morelet's crocodile is the jaguar (Panthera onca). Predation of a Morelet's crocodile by a jaguar was captured for the first time on a camera trap in the Calakmul Biosphere Reserve of Yucatán, Mexico in 2019. [47]

Reproduction

Six-month-old, at Tiergarten Schonbrunn Crocodylus moreletii - 6 month old.JPG
Six-month-old, at Tiergarten Schönbrunn
Baby Morelet's crocodiles at the Cotswold Wildlife Park, England Cwpcrocs.jpg
Baby Morelet's crocodiles at the Cotswold Wildlife Park, England

Breeding usually takes place between April and June, [24] and the eggs are laid before the start of the rainy season. Morelet's crocodile is unique among North American crocodiles in that it builds mound nests only, and not mound and hole nests. These mound nests are about 3 m (10 ft) wide and 1 m (3 ft 3 in) high and can be found near the water or on floating vegetation. A female crocodile can lay between 20 and 45 eggs, and nests have been found containing eggs from more than one female. The eggs are buried, and the nests are guarded by females. The eggs usually hatch after 80 days, [24] and hatchlings are normally about 17 cm (6+1⁄2 in) long. [4] After the eggs have hatched, the female crocodile will carry her young to the water, where they are protected by both parents. Females are highly protective of their young and have reportedly been observed to aggressively displace intruders and humans if distress calls of the baby crocodiles are heard, and even father crocodiles have been observed to spring to the defense of young crocodiles. [48] [49] In captivity, juvenile crocodiles – but never hatchlings – are treated aggressively by adult crocodiles. [50]

Conservation

Morelet's crocodile has long been threatened by habitat destruction and illegal hunting. [51] Both of these factors have significantly lowered its populations. It was hunted for its hide during the 1940s and 1950s [51] because high-quality leather can be made from its skin. [52] [53]

Notes

    References

    1. ↑ Rio, Jonathan P.; Mannion, Philip D. (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 Platt, S.G.; Sigler, L.; Rainwater, T.R.; Cedeño-Vázquez, J.R.; Villegas, A. (2023). "Crocodylus moreletii ". IUCN Red List of Threatened Species . 2023 e.T5663A193672551. doi: 10.2305/IUCN.UK.2023-1.RLTS.T5663A193672551.en . Retrieved 1 April 2024.
    3. 1 2 Species Crocodylus moreletii at The Reptile Database www.reptile-database.org.
    4. 1 2 "Crocodilians species (CSG)". Archived from the original on 2009-07-26.
    5. ↑ "Crocodylus moreletii Dumeril and Bibron 1851 (Morelet's crocodile)". PBDB.
    6. 1 2 3 4 Britton, Adam (2009). "Crocodylus moreletii (BIBRON & DUMERIL, 1851)". Crocodilians Natural History and Conservation. Howard Springs, Australia.
    7. ↑ Beolens, B.; Watkins, M.; Grayson, M. (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN   978-1-4214-0135-5. (Crocodylus moreletii, p. 182).
    8. 1 2 3 Hekkala, E.; Gatesy, J.; Narechania, A.; Meredith, R.; Russello, M.; Aardema, M. L.; Jensen, E.; Montanari, S.; Brochu, C.; Norell, M.; Amato, G. (2021). "Paleogenomics illuminates the evolutionary history of the extinct Holocene "horned" crocodile of Madagascar, Voay robustus ". Communications Biology. 4 (1): 505. doi: 10.1038/s42003-021-02017-0 . ISSN   2399-3642. PMC   8079395 . PMID   33907305.
    9. ↑ Oaks, Jamie R. (2011). "A time-calibrated species tree of Crocodylia reveals a recent radiation of the true crocodiles". Evolution. 65 (11): 3285–3297. Bibcode:2011Evolu..65.3285O. doi: 10.1111/j.1558-5646.2011.01373.x . PMID   22023592. S2CID   7254442.
    10. ↑ Lee, Michael S.Y.; Yates, Adam M. (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.
    11. ↑ Sales-Oliveira, V.; Altmanová, M.; Gvoždík, V.; Kretschmer, R.; Ezaz, T.; Liehr, T.; Padutsch, N.; Badjedjea G.; Utsunomia, R.; Tanomtong, A.; Ciof, M. (2023). "Cross‑species chromosome painting and repetitive DNA mapping illuminate the karyotype evolution in true crocodiles (Crocodylidae)". Chromosoma. 132 (4): 289–303. doi:10.1007/s00412-023-00806-6. PMID   37493806.
    12. ↑ Guggisberg, C.A.W. (1972). Crocodiles: Their Natural History, Folklore, and Conservation. Newton Abbot: David & Charles. p. 195. ISBN   0-7153-5272-5.
    13. 1 2 3 Platt, S.G.; Rainwater, T.R.; Thorbjarnarson, J.B.; Finger, A.G.; Anderson, T.A.; McMurry, S.T. (2009). "Size estimation, morphometrics, sex ratio, sexual size dimorphism, and biomass of Morelet's crocodile in northern Belize". Caribbean Journal of Science45 (1): 80–93.
    14. ↑ Barrios-Quiroz, G.; Casas-Andreu, G.; Escobedo-Galván, A.H. (2012). "Sexual size dimorphism and allometric growth of Morelet's crocodiles in captivity". Zoological Science29 (3): 198–203.
    15. ↑ Platt, S.G. (1996). The ecology and status Morelet's crocodile in Belize. Unpublished PhD Thesis, Clemson University, USA.
    16. 1 2 ""Morelet's Crocodile." Belize Zoo. 2007". Archived from the original on 2007-10-13.
    17. ↑ Erickson, Gregory M.; Gignac, Paul M.; Steppan, Scott J.; Lappin, A. Kristopher; Vliet, Kent A.; Brueggen, John D.; Inouye, Brian D.; Kledzik, David; Webb, Grahame J.W. (2012). "Insights into the Ecology and Evolutionary Success of Crocodilians Revealed through Bite-Force and Tooth-Pressure Experimentation". PLoS One. 7 (3) e31781. Bibcode:2012PLoSO...731781E. doi: 10.1371/journal.pone.0031781 . PMC   3303775 . PMID   22431965.
    18. ↑ "ADW: Crocodylus moreletii: CLASSIFICATION".
    19. 1 2 Sideleau, Brandon (2014). "Details of a fatal attack on a human by a Morelet's crocodile (Crocodylus moreletii) in Belize". IUCN Crocodile Specialist Group Newsletter. 33 (2): 29–30.
    20. ↑ Webb, G. (2009). "First record of a Morelet's crocodile in the Grijlava River, Chiapas, Mexico" (PDF). Crocodile Specialist Group Newsletter. 28 (2). IUCN - Species Survival Commission: 14.
    21. ↑ Dever, J.A; Strauss, Richard E.; Rainwater, Thomas R.; McMurry, Scott T.; Densmore, Llewellyn D. III (2002). "Genetic Diversity, Population Subdivision, and Gene Flow in Morelet's Crocodile (Crocodylus moreletii) from Belize, Central America". Copeia. 2002 (4): 1078–1091. doi:10.1643/0045-8511(2002)002[1078:GDPSAG]2.0.CO;2.
    22. ↑ C. Michael Hogan; World Wildlife Fund (2012). M. McGinley (ed.). "Belizean pine forests". Encyclopedia of Earth. Washington DC.
    23. 1 2 ""Freshwater Crocodile." Australia Zoo". Archived from the original on 2014-02-27. Retrieved 2007-12-14.
    24. 1 2 3 4 Navarro, Carlos. ""The Return of the Morelet's Crocodile." Reptilia" (PDF). Archived from the original (PDF) on 2016-03-04. Retrieved 2007-12-14.
    25. ↑ Archived at Ghostarchive and the Wayback Machine : "Capturan un cocodrilo en el Río Bravo; alertan sobre peligro". YouTube . 10 December 2012. (in Spanish).
    26. ↑ "Archived copy". Archived from the original on 2016-12-02.{{cite web}}: CS1 maint: archived copy as title (link)
    27. ↑ "Los inmigrantes enfrentan un nuevo peligro en el Río Bravo: cocodrilos". El Nuevo Diario. Archived from the original on 2014-09-06. Retrieved 2014-09-04. (in Spanish).
    28. ↑ "Capturan a cocodrilo en casa de Tamaulipas ". (in Spanish).
    29. ↑ "Gators at busy Matamoros shopping center : News: ValleyCentral.com". Archived from the original on 2014-09-05.
    30. ↑ "Reportan avistamientos de cocodrilos en las lagunas de la JAD de Matamoros – Hora Cero". Archived from the original on 2014-09-05. Retrieved 2014-09-04. (in Spanish).
    31. ↑ "Reynosa 'alligator' could be a crocodile". Archived from the original on 2014-09-24.
    32. ↑ "Capturan cocodrilo en el Río Bravo". (in Spanish).
    33. ↑ "Alertan en Reynosa por presencia de cocodrilos en río Bravo". Archived from the original on 2014-09-04. Retrieved 2014-09-04. (in Spanish).
    34. ↑ "Side Step - Reynosa 'alligator' could be a crocodile". 16 September 2008.
    35. ↑ "Reynosa man earns nickname 'Crocodile Hunter' : News: ValleyCentral.com". Archived from the original on 2014-09-05.
    36. ↑ "Reynosa family finds crocodile in their home : News: ValleyCentral.com". Archived from the original on 2014-09-05.
    37. ↑ "Fishermen catch crocodile in Rio Grande". NBC News . 9 October 2006.
    38. ↑ "Crocodile caught in the Rio Grande". San Diego Union-Tribune. October 24, 2025. Archived from the original on 2014-09-05.
    39. ↑ "Para acabarla de amolar, crecida de agua trae víboras, lagartos y alimañas ". (in Spanish).
    40. 1 2 Platt, S.G.; Rainwater, T.R.; Finger, A.G.; Thorbjarnarson, J.B.; Anderson, T.A.; McMurry, S.T. (2006). "Food habits, ontogenetic dietary partitioning and observations of foraging behaviour of Morelet's crocodile (Crocodylus moreletii) in northern Belize". The Herpetological Journal16 (3): 281–290.
    41. ↑ "Crocodilian Species - Morelet's Crocodile (Crocodylus moreletii)".
    42. ↑ Pérez-Higareda, G.; Rangel-Rangel, A.; Smith, H.M.; Chiszar, D. (1989). "Comments on the food and feeding habits of Morelet's Crocodile". Copeia1989: 1039–1041.
    43. ↑ Platt, S.G.; Rainwater, T.R.; Snider, S.; Garel, A.; Anderson, T.A.; McMurry, S.T. (2007). "Consumption of large mammals by Crocodylus moreletii: field observations of necrophagy and interspecific kleptoparasitism". Southwestern Naturalist52 (2): 310–317.
    44. ↑ "OpenDataSoft — CrocBITE Live Feed". Archived from the original on 2017-08-13.
    45. ↑ Marlin, J.A.; Marlin, K.K.; Platt, S.G. (1995). "A documented case of an attack by Morelet's crocodile (Crocodylus moreletii) on man". Bulletin of the Chicago Herpetological Society30: 165–167.
    46. ↑ Sideleau, B.; Britton, A.R.C. (2012). "A preliminary analysis of worldwide crocodilian attacks". In: Crocodiles Proceedings of the 21st Working Meeting of the IUCN-SSC Crocodile Specialist Group. Gland, Switzerland: IUCN (pp. 111–114).
    47. ↑ Simá-Pantí, David E.; Contreras-Moreno, Fernando M.; Mayor, Carlos Coutiño-Cal y; Zúñiga-Morales, José A.; Martin, Gabriela Méndez-Saint; Reyna-Hurtado, Rafael A. (2020-03-04). "Morelet's crocodile predation by jaguar in the Calakmul Biosphere Reserve in southeastern México". Therya Notes. 1: 8–10. doi: 10.12933/therya_notes-20-3 . ISSN   2954-3614.
    48. ↑ Álvarez del Toro, M.; Sigler, L. (2001). Los Crocodylia de México. México, Distrito Federal: IMRNR-PROFEPA.
    49. ↑ Rainwater, T.R.; McMurry, S.T; Platt, S.G. (2000). "Crocodylus moreletii (Morelet's crocodile) behavior". Herpetological Review31: 237.
    50. ↑ Hunt, R.H. (1977). "Aggressive Behavior by Adult Morelet's Crocodiles Crocodylus moreleti [sic] toward Young". Herpetologica33 (2): 195–201.
    51. 1 2 Espinosa, Eduardo (1998). "Crocodylus moreletii." Florida Museum. ISBN   978-2-8317-0441-8.
    52. ↑ Platt, Steven; Thorbjarnarson, John (2000). "Population status and conservation of Morelet's Crocodile, Crocodylus moreletii, in northern Belize". Biological Conservation. 96: 21–29.
    53. ↑ King, F.W. (2002). "The Crocodile Specialist Group". Crocodile Specialist Group. Archived from the original on 2007-12-28.
    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.