Boas classification

Boidea (58 species) is a superfamilly of popular boas. Inside this taxa we don't find anymore calabar ground python. Long time ago he was classified as python but actually he isn't python nor boa and form another his own superfamilly Calabariidea (with one species). However Calabaria reinhardi (calabar ground boa or calabaria) is still in Erycinae family (old world sand boas) which ones he is isn't close relatives. I need to mention that this still will change because Sanziniinae are paraphiletictaxa (not all relatives are in this group), One of the biggest differences between calabria and boas are in the methods of reproduction. Boas are viviparous and calabarias are oviparous. 

In endemic Madagascar boas (Sanziniinae) are no longer single species but two. The subspecies S. madagascarensis volontany has been raised to species status. In genus Arcantophis are still some unsure systematic positions but this needed further studies.

Calabaria from http://www.inaturalist.org if you look closely you will see that his tail resemblance head!

Subfamilly Erycinae are not longer contain Lichanura, Charina,  Exilboa and Ungaliophis (ground boas). Yhey are expelled from Erycinae and form their own subfamilly Ungaliophidae. There are also clear that Lichanura and Charina are genus reserved for New world while Exilboa and Ungaliophis for Old world. So if you ever read about species from Charina genus you will automatically known that this snake is from New world. In genus Eryx we can suspect in future few new species. 

Very interesting genus Candoia form his own subfamilly Candoinae and they are closely related to Boinae. The very interesting thing about this genus is that the live on far away land from Boinae homeland. They are distributed on Melanseia, Micronesia, Papua New Guinea islands where all Boinae are reserved to New world.

Boas phylogeny from Rawlings et al 2014.

There is interesting information for boa constrictor keepers! They are in familly Boinae and subspecies of boa constrictor B. c. imperator are now species Boa imperator. In future in this genus we can also expect some changes.

In genus Corallus nothing change now although we can assume that in future Corallus hortulanus can be divided on different species.

Amazon tree boa from http://www.coralluscaninus.info aren't they sweeties?

All anacondas (Eunectes genus) are the closest relatives of rainbow boas (Epicrates). Well they are don't so similar to each other when you look at them. However the molecular and genetic research proof that they are close relatives (they are sharing common ancestor). Some species are no longer in Epicrates but they are form different genus Chilabothrus (west Indian boas).  If you have for example Hispaniolan boa (C. striatus) he is not longer Epicrates but Chilabothrus. All species from Epicrates are reserved to South American mainland and Chilabothrus to West Indian Islands.

Yep that's all I'v hope that you are enjoyed my article and you are glad to hear that B. imperatus are species not subspecies. 

If you want fell free to post a comment below, I would greatly appreciate any feedback.

What is your favorite boa share below your favorite species and/or morph of this amazing creatures.

Is hard to decide which one i love the most so I post there two! :P

   Emerald tree boa  (from calphotos.berkeley.edu)                                                  Amazon tree boa                                                                                                                                      Halloween morph                                                                                                             (from http://www.une-saison-en-guyane.com)

Interesting literature:

1. Austin, C.C., 2000. Molecular Phylogeny and Historical Biogeography of Pacific Island Boas (Candoia). Copeia 2000, 341–352. doi:10.1643/0045-8511(2000)000[0341:MPAHBO]2.0.CO;2
2. Boback, S.M., 2005. Natural History and Conservation of Island Boas (Boa Constrictor) in Belize. Copeia 2005, 879–884. doi:10.1643/0045-8511(2005)005[0879:NHACOI]2.0.CO;2
3. Chiaraviglio, M., Bertona, M., Sironi, M., Lucino, S., 2003. Intrapopulation variation in life history traits of Boa constrictor occidentalis in Argentina. Amphibia and Reptilia. 24, 65–74.
4. Colston, T.J., Grazziotin, F.G., Shepard, D.B., Vitt, L.J., Colli, G.R., Henderson, R.W., Blair Hedges, S., Bonatto, S., Zaher, H., Noonan, B.P., Burbrink, F.T., 2013. Molecular systematics and historical biogeography of tree boas (Corallus spp.). Molecular Phylogenetic Evolution 66, 953–959. doi:10.1016/j.ympev.2012.11.027
5. Henderson, R.W., 1997. A taxonomic review of the Corallus hortulanus complex of Neotropical tree boas. Caribbean Journal of Science. 33, 198–221.
6. Henderson, R.W., Pauers, M.J., Colston, T.J., 2013. On the congruence of morphology, trophic ecology, and phylogeny in Neotropical treeboas (Squamata: Boidae: Corallus). Biological Journal of the Linnean Society 109, 466–475.
7. Hynková, I., Starostová, Z., Frynta, D., 2009. Mitochondrial DNA Variation Reveals Recent Evolutionary History of Main Boa constrictor Clades. Zoological Science 26, 623–631. doi:10.2108/zsj.26.623
8. Martins, M., Oliviera, M.E., 1999. Natural History of snakes in Forests in the Manaus Region Central Amazonia, Brazil. Natural History Notes 6, 78–150.
9. Monteiro, L.R., 1998. Ontogcnetic changes in the skull of Corallus caninus L., 1758 and Corallus enydris L., 1758 (Serpentes: Boidae), an allometric study. SNAKE-NITTAGUN- 28, 51–58.
10. Noonan, B.P., Chippindale, P.T., 2006a. Dispersal and vicariance: the complex evolutionary history of boid snakes. Molecular Phylogenetic Evolution 40, 347–58. doi:10.1016/j.ympev.2006.03.010
11. Noonan, B.P., Chippindale, P.T., 2006b. Vicariant Origin of Malagasy Reptiles Supports Late Cretaceous Antarctic Land Bridge. American Naturalist 168, 730–741. doi:10.1086/509052
12. Noonan, B.P., Sites Jr., J.W., 2010. Tracing the Origins of Iguanid Lizards and Boine Snakes of the Pacific. American Naturalist 175, 61–72. doi:10.1086/648607
13. Orozco-Terwengel, P., Nagy, Z.T., Vieites, D.R., Vences, M., Louis Jr, E., 2008. Phylogeography and phylogenetic relationships of Malagasy tree and ground boas. Biological Journal of the Linnean Society. 95, 640–652. doi:10.1111/j.1095-8312.2008.01083.x
14. Pizzatto, L., Marques, O.A., Facure, K., 2009. Food habits of Brazilian boid snakes: overview and new data, with special reference to Corallus hortulanus. Amphibia - Reptilia. 30, 533–544.
15. Pyron, R.A., Burbrink, F.T., Wiens, J.J., 2013. A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evolutionary Biology 13, 93. doi:10.1186/1471-2148-13-93
16. Reynolds, R.G., Niemiller, M.L., Hedges, S.B., Dornburg, A., Puente-Rolón, A.R., Revell, L.J., 2013. Molecular phylogeny and historical biogeography of West Indian boid snakes (Chilabothrus). Molecular Phylogenetic Evolution 68, 461–470. doi:10.1016/j.ympev.2013.04.029 48
17. Reynolds, R.G., Niemiller, M.L., Revell, L.J., 2014. Toward a Tree-of-Life for the boas and pythons: Multilocus species-level phylogeny with unprecedented taxon sampling. Molecular Phylogenetic Evolution 71, 201–213. doi:10.1016/j.ympev.2013.11.011

Pythons classification

Popular pythons form superfamilly Pythonidea and they are represent by 43 species (but expect more in future). Inside this superfamilly we have three families. First the most basal from them are Xenopeltidae (south-east Asian sunbeam snakes), Loxocemidae (Mexican Burrowin pythons) and of course Pythonidae. You are probably know that pythons are live in old world (Asia, Australia, Europe, Africa) and s-e Asian sunbeam snakes so what Mexican burrowing pythons doing in middle America. This is related with continental drift. Pythons evolved in Gondwanaland where all continents stick together. When continents start to divide some groups of animals are isolated on this swimming masses of land. Some of them menage to survive and this is the most probable scenario of distant living location of Mexican burrowing pythons. 

But back to topic. In newest research the most basal group (not primitive but they are more old in philogenetically terms than other pythons) are genus Python. Inside this genus we find for example African rock python and the most basal of all pythons Python regius probably the most widely breeded snake and better known under ball python name.

African rock python (P. sebae) from www.bbc.co.uk/nature/life/Python_sebae

We know that genus Python had heave inside a intruder, a reticulated python. Now reticulated python along with Timor python are form different taxa - Malayopython. In wide range of websites (wikipedia for example) they are still named as Python reticulatus or Python timorensis where they should be called Malayopython reticulatus and M. timorensis. However it is possible that in future genus Malayopython will have more species than those two.Why scientist wanted to divide this genus? Because reticulated python are more similar to Australian group of pythons instead of African and Asian mainland genus Python. Not that long ago reticulated python weren't in genus Python nor Malayopython but in Broghammerus. However the name Broghammerus was use against taxonomical law by R. Hoser. Mr Hoser have ability to be really problematic for taxonomists but abut that I say more another time. To help you move in this cclassificational dimension I share with you phylograme of pythons ( from Reynolds et al., 2014).

Reticulated python (M. reticulatus) from http://calphotos.berkeley.edu/

As you can see below on the top are most basal species and on bottom are the most advanced Australian species. Following those lines from left you can see that they are always divided on two. This way you can check what species are the closest relatives to another. 

Phylogeny of pythons and their distribution from Rawlings et al. 2014

In Australian pythons group we can see even more changes. Genus Morelia have been divided in two different groups. One group is carpet/tree pythons group and second one is group of amethystine/scrub pythons. All carpet and tree pythons are stay in genus Morelia but all amethystine pythons are move to genus Simalia. For example amethystine python are no longer Morelia amethystina but Simalia amethistina. In genus Simalia are a lot of new species thankfully for work of  (Schleip, 2008). In green tree python (Morelia viridis) populary named chondro (from their older name Chondropython). This is great that in future we could have two green tree python species Morelia viridis and Morelia azurea what I find very exciting. Also in carpet pythons it is possible that there are other species but there is needed more research. 

Moluccan python (S. clastolepis) from moreliapythonradio.com

As you can see on phylogramme above the sister genus to Morelia (closest relatives) are Antaresia who is popularly known as Children's pythons. Inside this genus I didn't notice any changes so lets move on. 

Next genus Liasis have some surprises for us. The olive python are no longer in their own genus Apodora but in Liasis. Liasis papuanus (olive python) could have cryptic species (not currently described). 

Olive python (L. olivaceus) from gondwanareptilesproductions.com

Genus Aspidites was prefiously taken by the most basal genus of all pythons (because they lack of thermal pits). However along with molecular data their status turn out to be one of the most advanced of all pythons. In genus Aspidites we can find small pythons dwelling on the ground and eating lizards and that's the reason why they lost thermal pits. Lizards are coldblooded (exothermic) so they have temperature as surroundings. In that way thermal pits were useless. They adapted to their prey and lost their thermoreceptic organ. Although pythons along with boas and vipers are known for having thermoreceptic organ the most important of all senses in snakes are chemoreceptive organ. That one which involved uses of divided tongue.

The last genus of pythons is Bothrochilus. This genus where old times was only Bothrochilus boa (Bismarck python) was merged with Leiopython. In this case Leiopython (D'alberts water pythons) are not longer exist and all old Leiopython species are now in Bothrochilus. In this genus we can also notice that there are no longer so few species. Instead of three species we can find there even seven species!

White - lipped python (B. alberisii) from http://www.natureswindow.dk/

where by the way he is still described as Leiopython.

I know that topic could be a little bit hard to follow and not all of you will enjoy reading it as I writing. Nevertheless I'm hoping that you will learn some new things and be at least surprised for those changes. And as you can see there is a lot of news in pythons. 

Look forward to new posts because next time I will write about classification of boas!

If you will have any questions feel free to ask me below.

Interesting literature:

1.             Noonan, B.P., Chippindale, P.T., 2006a. Dispersal and vicariance: the complex evolutionary history of boid snakes. Molecular Phylogenetic Evolution 40, 347–58. doi:10.1016/j.ympev.2006.03.010
2.              O’Shea, M., 2011. Boas & Pythons of the World. New Holland Publishers Ltd, London.
3.              Pyron, R.A., Burbrink, F.T., Wiens, J.J., 2013. A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evolutionary Biology 13, 93. doi:10.1186/1471-2148-13-93
4.              Rawlings, L.H., Barker, D., Donnellan, S.C., 2004. Phylogenetic relationships of the Australo-Papuan Liasis pythons (Reptilia : Macrostomata), based on mitochondrial DNA. Australian Journal of the Zoology. 52, 215–227.
5.             Rawlings, L.H., Donnellan, S.C., 2003. Phylogeographic analysis of the green python, Morelia viridis, reveals cryptic diversity. Molecular Phylogenetic Evolution. 27, 36–44. doi:10.1016/S1055-7903(02)00396-2
6.             Rawlings, L.H., Rabosky, D.L., Donnellan, S.C., Hutchinson, M.N., 2008. Python phylogenetics: inference from morphology and mitochondrial DNA. Biological Journal of the Linnean Society. 93, 603–619.
7.             Reynolds, R.G., Niemiller, M.L., Revell, L.J., 2014. Toward a Tree-of-Life for the boas and pythons: Multilocus species-level phylogeny with unprecedented taxon sampling. Molecular Phylogenetic Evolution 71, 201–213. doi:10.1016/j.ympev.2013.11.011
8.                Schleip, W., O’Shea, M., 2010. Annotated checklist of the recent and extinct pythons (Serpentes, Pythonidae), with notes on nomenclature, taxonomy, and distribution. ZooKeys 66. doi:10.3897/zookeys.66.683
9.              Schleip, W.D., 2008. Revision of the Genus Leiopython Hubrecht 1879 (Serpentes: Pythonidae) with the Redescription of Taxa Recently Described by Hoser (2000) and the Description of New Species. Journal of Herpetology. 42, 645–667. doi:10.1670/06-182R5.1
10.             Wiens, J.J., Hutter, C.R., Mulcahy, D.G., Noonan, B.P., Townsend, T.M., Sites, J.W., Reeder, T.W., 2012. Resolving the phylogeny of lizards and snakes (Squamata) with extensive sampling of genes and species. Biology Letters 8, 1043–1046. doi:10.1098/rsbl.2012.0703

Current taxonomy of Boas and Pythons

Squamata (~ 9,556 species) was traditionally divided for lizards, worm lizards (Aphisbaenia) and snakes. New research founding however disagree with this taxonomy and establish that old divisions are paraphyletic (not all descendants are within right taxa). (To check snakes phylogeny follow names with green lines.) Currently we recognize five subordo Dibamidae, Gekkota, Scincimorfa, Lacertata and Toxicofera. Our beloved animals (snakes) are in Toxicofera subordo what you can see in graphic below. This group of animals are known for using venom (YES! Iguania and Anguimorpha distant relatives used venom in the past). Within Toxicofera we distinguish anguimorpha, iguanas and snakes. This taxa started to use venom approx 200 my ago in Triassic period. It's hard now to say what of this taxa are sister lineage to snakes (closest relatives). 

At present we recognize ~ 3,458 species of snakes which makes them one of the biggest taxa in all reptiles and even between other classes. And what is the most exciting thing there? - the species number in snakes still growths! Inside snakes we have simple division on two. First are basal Scoleocophidia (popular blind snakes) and the second one is Alethinophidia (true snakes). Because pythons and boas are Alethinophidians I will follow more deeply in this direction. As you can see below Alethinophidia are divide on another two taxa: Henophidia and Caenophidia (where Henophidia are more basal one). 

P. Puszkiewicz "Cranial morphology analysis in Pythonidae and Boidae in philogenetical and ecological context" 2014.

Now can be little bit harder.  We know now that pythons and boas are within Henophidia taxa but there is another artificial division for Macrostomata. Snakes in this taxa have ability to open they jaw widely or more simple snakes with large gapes. Inside Macrostomata we have also Caenophidia where we classified snakes such as cobras and vipers. Caenophidia are commonly known as advanced snakes and in this taxa we found most of the most venomous snakes. However they are don't interest us now we are curious about core Macrostomatan taxa - pythons and boas. They both contains 101 species which is quite nice number. As you can see pythons are don't longer within boas taxa. There are clear that this two groups are philogenetcially more distant than we thought (they are not close relatives). The similarities between boas and pythons are mostly results of similar ecology. We call this convergent evolution. These both groups are mirrors each other but there are some clear differences which about I write more in near future. We don't know everything about their origins but we can suspect that they are originated on earlier cretaceous Gondwanaland, and they divided from each other 40-30 my later.

To sum up this post  they are within Toxicofera taxa where are all reptiles with venom glands. Boas and pythons are also Alethinophidians and Henophidians. They also have possibility to largely open their gape (Macrostomata) in contrast to Uropeltidae for example. In the past pythons was classified as subfamilly of Boidae. Pythons are not boas! they form different taxa they are don't even sister taxa. Why I need to scream about that - because there are still places where they are grouped together.

Next time I will write more closely about pythons and boas because there are even more taxonomical changes!

Do you think that this changes are good or you prefer old classification?

Comment below and let me know what do you think.

Useful research papers

1.      Fry, B.G., Vidal, N., Norman, J.A., Vonk, F.J., Scheib, H., Ramjan, S.F.R., Kuruppu, S., Fung, K., Blair Hedges, S., Richardson, M.K., Hodgson, W.C., Ignjatovic, V., Summerhayes, R., Kochva, E., 2006. Early evolution of the venom system in lizards and snakes. Nature 439, 584–588. doi:10.1038/nature04328

2.      Fry, B.G., Vidal, N., van der Weerd, L., Kochva, E., Renjifo, C., 2009. Evolution and diversification of the Toxicofera reptile venom system. Journal of Proteomics 72, 127–136. doi:10.1016/j.jprot.2009.01.009

3.      Greene, H.W., Burghardt, G.M., 1978. Behavior and phylogeny: constriction in ancient and modern snakes. Science 200, 74–77. doi:10.1126/science.635575

4.      Kluge, A.G., 1991. Boine snake phylogeny and research cycles. Miscellaneous Publications of Michigan Museum of Zoology.

5.      Noonan, B.P., Chippindale, P.T., 2006. Dispersal and vicariance: the complex evolutionary history of boid snakes. Molecular Phylogenetic Evolution 40, 347–58. doi:10.1016/j.ympev.2006.03.010

6.      O’Shea, M., 2011. Boas & Pythons of the World. New Holland Publishers Ltd, London.

7.      Pyron, R.A., Burbrink, F.T., Wiens, J.J., 2013. A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evolutionary Biology 13, 93. doi:10.1186/1471-2148-13-93

8.      Reynolds, R.G., Niemiller, M.L., Revell, L.J., 2014. Toward a Tree-of-Life for the boas and pythons: Multilocus species-level phylogeny with unprecedented taxon sampling. Molecular Phylogenetic Evolution 71, 201–213. doi:10.1016/j.ympev.2013.11.011

9.      Schleip, W., O’Shea, M., 2010. Annotated checklist of the recent and extinct pythons (Serpentes, Pythonidae), with notes on nomenclature, taxonomy, and distribution. ZooKeys 66. doi:10.3897/zookeys.66.683

10.      Vidal, N., Delmas, A.-S., Hedges, S.B., 2007. The higher-level relationships of alethinophidian snakes inferred from seven nuclear and mitochondrial genes. Biology of Boas and Pythons 27–33.

11.      Vidal, N., Hedges, S.B., 2009. The molecular evolutionary tree of lizards, snakes, and amphisbaenians. Comptes Rendus Biologies. 332, 129–139. doi:10.1016/j.crvi.2008.07.010

12.      Wiens, J.J., Hutter, C.R., Mulcahy, D.G., Noonan, B.P., Townsend, T.M., Sites, J.W., Reeder, T.W., 2012. Resolving the phylogeny of lizards and snakes (Squamata) with extensive sampling of genes and species. Biology Letters 8, 1043–1046. doi:10.1098/rsbl.2012.0703