Colubridae Explained

Colubridae (commonly known as colubrids, from Latin: coluber, 'snake') is a family of snakes. With 249 genera,[1] it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected.[2] Colubrid snakes are found on every continent except Antarctica.[3]

Description

Colubrids are a very diverse group of snakes. They can exhibit many different body styles, body sizes, colors, and patterns. They can also live in many different types of habitats including aquatic, terrestrial, semi-arboreal, arboreal, desert, mountainous forests, semi-fossorial, and brackish waters.[4] A primarily shy and harmless group of snakes, the vast majority of colubrids are not venomous, nor do most colubrids produce venom that is medically significant to mammals. However, the bites of a few groups (such as Boiga sp.) can escalate quickly to emergency situations. Furthermore, within the Colubridae, the South African boomslang and twig snakes, as well as the Asian keelback snakes (Rhabdophis sp.) have long been notorious for inflicting the worst bites on humans, with the most confirmed fatalities.[3] [5] [6]

Some colubrids are described as opisthoglyphous (often simply called "rear-fanged"), meaning they possess shortened, grooved "fangs" located at the back of the upper jaw. It is thought that opisthoglyphy evolved many times throughout the natural history of squamates[5] and is an evolutionary precursor to the larger, frontal fangs of vipers and elapids.[7] [8] [9] [3] [5] These grooved fangs tend to be sharpest on the anterior and posterior edges.[10] While feeding, colubrids move their jaws backward to create a cutting motion between the posterior edge and the prey's tissue. In order to inject venom, colubridae must chew on their prey.[11] Colubrids can also be proteroglyphous (fangs at the front of the upper jaw, followed by small solid teeth)[4]

Most Colubridae are oviparious (mode of reproduction where an egg is produced that will later hatch) with clutch size varying by size and species of snake. However, certain species of snakes from the subfamilies of Natriciinae and Colubrinae are viviparous (mode of reproduction where young are live birthed). These viviparous species can birth various amounts of offspring at a time, but the exact number of offspring depends on the size and species of snake [4]

Characteristics of Colubridae

Characteristics of Colubridae include limbless bodies, left lung that is reduced or absent, tracheal lung that is reduced or absent, well-developed oviducts, Premaxillaries that lack teeth, maxilaries oriented longitudinally with teeth that are solid or grooved, mandible does not have coronoid bone, dentary that has teeth, only a left carotid artery, Intercostal arteries from the dorsal aorta in trunk segments, no cranial infrared receptors occur in pits or surface indentations, and an optic foramina that usually perforate the frontal–parietal–parasphenoid sutures [4]

Classification

In the past, the Colubridae were not a natural group, as many were more closely related to other groups, such as elapids, than to each other.[12] This family was historically used as a "wastebasket taxon"[6] for snakes that do not fit elsewhere.[13] Until recently, colubrids were basically colubroids that were not elapids, viperids, or Atractaspis.[14]

However, recent research in molecular phylogenetics has stabilized the classification of historically "colubrid" snakes and the family as currently defined is a monophyletic clade,[15] [16] [17] [18] although additional research will be necessary to sort out all the relationships within this group. As of May 2018, eight subfamilies are recognized.[19]

Current subfamilies

Sibynophiinae – three genera

Natricinae – 36 genera (sometimes given as family Natricidae)

Pseudoxenodontinae – two genera

Dipsadinae – over 100 genera (sometimes given as family Dipsadidae)

Grayiinae – one genus

Calamariinae – seven genera

Ahaetuliinae – five genera

Colubrinae – 93 genera

Sub-family currently undetermined

Former subfamilies

These taxa have been at one time or another classified as part of the Colubridae, but are now either classified as parts of other families, or are no longer accepted because all the species within them have been moved to other (sub)families.

Fossil record

The oldest colubrid fossils are indeterminate vertebrae from Thailand and specimens of the genus Nebraskophis from the U.S. state of Georgia, both from the Late Eocene. The presence of derived colubrids in North America so early on, despite their presumed Old World origins, suggests that they originated even earlier. The Pliocene (Blancan) fossil record in the Ringold Formation of Adams County, Washington has yielded fossils from a number of colubrids including Elaphe pliocenica, Elaphe vulpina, Lampropeltis getulus, Pituophis catenifer, a Thamnophis species, and the extinct genus Tauntonophis.[23]

References

Bibliography

External links

Notes and References

  1. Web site: Colubrid . britannica.com . Britannica . 2 December 2018 . 3 December 2018 . https://web.archive.org/web/20181203013937/https://www.britannica.com/animal/colubrid . live.
  2. Book: P Dennis . Nebraskophis HOLMAN from the Late Eocene of Georgia (USA), the oldest known North American colubrid snake . A J . 2003.
  3. Book: Cogger, H.G.. Harold Cogger . Zweifel, R.G.. Richard G. Zweifel . Bauer, Aaron M. . 1998 . Encyclopedia of Reptiles and Amphibians . Academic Press . San Diego . 188–195 . 978-0-12-178560-4 .

    fr:Aaron Matthew Bauer

    .
  4. Vitt, Laurie J, and Janalee P Caldwell. Herpetology An Introductory Biology of Amphibians and Reptiles. 4th ed., Elsevier Inc, 2014.
  5. Bruna Azara, C. . 1995 . Animales venenosos. Vertebrados terrestres venenosos peligrosos para el ser humano en España . Boletín de la S.E.A. . 11 . 32–40 . 2016-09-30 . 2020-08-14 . https://web.archive.org/web/20200814031303/http://sea-entomologia.org/PDF/BOLETIN_11/B11-009-032.pdf . live.
  6. Book: 10.1016/C2010-0-68461-6 . "Venomous" Bites from Non-Venomous Snakes . 2011 . 978-0-12-387732-1 .
  7. Jackson . K . The evolution of venom-delivery systems in snakes . Zoological Journal of the Linnean Society . 2003 . 137 . 3 . 337–354 . 10.1046/j.1096-3642.2003.00052.x . free .
  8. Vonk . F. J. . Admiraal . J. F. . Jackson . K. . Reshef . R. . de Bakker . M. A. . Vanderschoot . K. . van den Berge . I. . van Atten . M. . Burgerhout . E.. Beck. A. . Evolutionary origin and development of snake fangs . Nature . 2008 . 454 . 7204 . 630–633 . 10.1038/nature07178 . 18668106 . 2008Natur.454..630V . 4362616 .
  9. Fry . B. G. . Casewell . N. R. . Wüster . W. . Vidal . N. . Young . B. . Jackson . T. N. . The structural and functional diversification of the Toxicofera reptile venom system . Toxicon . 2012 . 60 . 4 . 434–448 . 10.1016/j.toxicon.2012.02.013 . 22446061 . 2012Txcn...60..434F .
  10. Cleuren . Silke G. C. . Hocking . David P. . Evans . Alistair R. . June 2021 . Fang evolution in venomous snakes: Adaptation of 3D tooth shape to the biomechanical properties of their prey . Evolution . en . 75 . 6 . 1377–1394 . 10.1111/evo.14239 . 33904594 .
  11. Book: 10.1016/B978-0-12-824315-2.00652-7 . Snakes . Encyclopedia of Toxicology . 2024 . Schmalzried . Scott . Ceretto . Vincent . 567–571 . 978-0-323-85434-4 .
  12. Lawson . R. . Slowinski . J.B. . Crother . B.I. . Burbrink . F.T. . Phylogeny of the Colubroidea (Serpentes): New evidence from mitochondrial and nuclear genes . Molecular Phylogenetics and Evolution . November 2005 . 37 . 2 . 581–601 . 10.1016/j.ympev.2005.07.016 . 16172004 . 2005MolPE..37..581L .
  13. Fry, B.G. . Vidal, N. . van der Weerd, L. . Kochva, E. . Renjifo, C. . Evolution and diversification of the Toxicofera reptile venom system . 2009 . Journal of Proteomics . 72 . 2 . 127–136 . 10.1016/j.jprot.2009.01.009 . 19457354.
  14. Book: Pough . F. Harvey . R. M. . Cadle . J. E. . Crump . M. L. . Savitzky . A. H. . Wells . K. . Herpetology . 1998 . Prentice Hall . 978-0-13-850876-0 . 162 .
  15. Pyron . R. A. . Burbrink . F. . Wiens . J. J. . A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes . BMC Evolutionary Biology . 2013 . 13 . 1 . 93 . 10.1186/1471-2148-13-93 . 23627680 . 3682911 . 2013BMCEE..13...93P . free .
  16. Figueroa . A. . McKelvy . A. D. . Grismer . L. L. . Bell . C. D. . Lailvaux . S. P. . A species-level phylogeny of extant snakes with description of a new colubrid subfamily and genus . PLOS ONE . 2016 . 11 . 9 . e0161070 . 5014348 . 10.1371/journal.pone.0161070 . 27603205 . 2016PLoSO..1161070F . free.
  17. Pyron . R. A. . Burbrink . F. T. . Colli . G. R. . de Oca . A. N. M. . Vitt . L. J. . Kuczynski . C. A. . Wiens . J. J. . The phylogeny of advanced snakes (Colubroidea), with discovery of a new subfamily and comparison of support methods for likelihood trees . Molecular Phylogenetics and Evolution . 2011 . 58 . 2 . 329–342 . 10.1016/j.ympev.2010.11.006 . 21074626 . 2011MolPE..58..329P .
  18. Zheng . Yuchi . Wiens . John J. . Combining phylogenomic and supermatrix approaches, and a time-calibrated phylogeny for squamate reptiles (lizards and snakes) based on 52 genes and 4162 species . Molecular Phylogenetics and Evolution . January 2016 . 94 . Pt B . 537–547 . 10.1016/j.ympev.2015.10.009 . 26475614 . 2016MolPE..94..537Z .
  19. Web site: Uetz . Peter . Colubridae at The Reptile Database . The Reptile Database . EMBL . 13 May 2018 . 29 June 2018 . https://web.archive.org/web/20180629172949/http://reptile-database.reptarium.cz/advanced_search?taxon=Colubridae&submit=Search . live.
  20. Holman . J. Alan . 1982-01-01 . New Herpetological Species and Records from the Norden Bridge Fauna (Miocene: Late Barstovian) of Nebraska . Transactions of the Nebraska Academy of Sciences and Affiliated Societies.
  21. Web site: Floridaophis auffenbergi . 2023-12-15 . Florida Vertebrate Fossils . en-US.
  22. Savage . Jay M. . 2015 . What are the correct family names for the taxa that include the snake genera Xenodermus, Pareas, and Calamaria? . Herpetological Review . 46 . 4 . 664–665 . 2018-05-14 . https://web.archive.org/web/20160307141006/http://www.zenscientist.com/index.php/pdflibrary2/func-finishdown/2496 . 2016-03-07 . dead.
  23. Parmley . D. . Walker . D. . 2003 . Snakes of the Pliocene Taunton local fauna of Adams County, Washington with the description of a new colubrid . Journal of Herpetology . 37 . 2 . 235–244 . 10.1670/0022-1511(2003)037[0235:SOTPTL]2.0.CO;2. 86000331.

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