Hi Vera,

Salamanders are a northern, primarily temperate, group of amphibians. They and frogs originated in the Late Triassic/Early Jurassic. Frogs are known from South America in the Jurassic. Salamanders are not. To get to Australia in the Mesozoic, they would have had to go through South America and Antarctica, as frogs must have successfully done. Primitive frogs occur in New Zealand; they must have reached there via the South America-Antarctica-Australia route during the Mesozoic. Salamanders (plethodontids) have had a relatively recent (Late Cenozoic) incursion into northern South America from North/Central America, so they could not have taken the route to Australia that frogs did.

I dont think salamander fossils have been found in Australia. None in South America to until late in the Tertiary (perhaps only coming with greta biotic interchange though molecuar data suggests colonisation earlier) - ie they are a northern group and were absent in Gondwana

Hi Vera,

Salamanders are a northern, primarily temperate, group of amphibians. They and frogs originated in the Late Triassic/Early Jurassic. Frogs are known from South America in the Jurassic. Salamanders are not. To get to Australia in the Mesozoic, they would have had to go through South America and Antarctica, as frogs must have successfully done. Primitive frogs occur in New Zealand; they must have reached there via the South America-Antarctica-Australia route during the Mesozoic. Salamanders (plethodontids) have had a relatively recent (Late Cenozoic) incursion into northern South America from North/Central America, so they could not have taken the route to Australia that frogs did.

Hi James,

Do you have an article in mind that might address this hypothesis? 

Hi Vera,

This paper may help.

Cheers,

Nicholas

http://www.jstor.org/stable/pdf/10.1086/429523.pdf?_=1468450766563

Thanks so much all! That is so interesting and makes complete sense. Nick, your link didn't work - try this one below. So if this article is correct that amphibians diversified before Pangea broke up, we seem to be looking at biogeographical pot luck :-).

But it is interesting - this does not seem to have been written up anywhere recently.

http://www.journals.uchicago.edu/doi/abs/10.1086/429523

It is all about biogeography of the ancestral lines.  Think of the oldest amphibian.  It was something like today's salamanders.  Those were probably in Pangea with a distribution that was wide enough to explain how current amphibians are distributed.  Frogs are from Gondwanaland whereas salamanders seem to be from Laurasia.  The closest salamanders get to Australia is probably Vietnam and Laos.  And that's because their ancestors were from the northern super-continent (Laurasia).

Vera:

You may like to have a look at this link:

https://mickresearch.files.wordpress.com/2011/08/newtinvasion3.pdf

Best

Syed

I am not sure that you still need this information... But, maybe this could help you. 

Milner AR (1983) The biogeography of salamanders in the Mesozoic and Early Caenozoic: a cladistic-vicariance model. In: Sims RW, Price JH, Whalley PES (eds.), Evolution, time and space: the emergence of the biosphere. Syst Assoc Spec Vol 23. Academic Press, London, pp. 431–468

Hello Everyone!

Vera, actually, it is a very interesting question! I found reasonable that James wrote.

Elmer et al. (2013) made a nice contribution regarding the origin and diversification of South American Salamanders (link below).

(http://bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-13-59)

Rovito & Parra-Olea discussed some current facts regarding the Neotropical Pletodontid biogeography.

(https://www.researchgate.net/publication/299652607_Neotropical_Plethodontid_Biogeography_Insights_from_Molecular_Phylogenetics)

Regarding that Paulo wrote, I would like to share that currently are recognized five recognized species in the Brazilian Amazon Rainforest (link below).

(https://www.researchgate.net/profile/Marinus_Hoogmoed2/publication/283898288_Taxonomy_and_distribution_of_the_salamander_genus_Bolitoglossa_Dumeril_Bibron_Dumeril_1854_Amphibia_Caudata_Plethodontidae_in_Brazilian_Amazonia/links/5658771008aefe619b21035d.pdf)  

Kind Regards!

Article Neotropical Plethodontid Biogeography: Insights from Molecul...

Article Taxonomy and distribution of the salamander genus Bolitoglos...

Liebe Vera, 

ich kann Dir da leider nicht weiterhelfen. Die Erklärungen der Kollegen erscheinen logisch, also habe die Schwanzlurche es ähnlich wie die placentalen Säuger nicht geschafft, Australien zu besiedeln bevor es abbrach. Du könntest aber auch Prof. Dr. Wolfgang Böhme vom Museum Alexander Koenig in Bonn fragen, Er ist Con-Doktorand von mir und hat 1971, zwei Jahre nach mir bei Herre in Kiel promoviert. er hat sich zum international anerkannten Herpetologen in Bonn entwickelt. Seine Gebiete sind: Systematik, Ökologie und Zoogeographie der Amphibien und Reptilien. Er hat über 600 Publikationen veröffentlicht und ein Handbuch herausgegeben. Er wurrde 2011 pensioniert, ist aber weiter am Museum tätig. Seine e-mail lautet: [email protected] Schreib ihm doch einfach einmal. Du kannst Dich auf mich berufen und ihn von mir grüßen.

Es ist ein Versuch wert, Pensionäre haben etwas mehr Zeit und freuen sich meistens, wenn sie noch gefragt werden.

Ich hoffe, es geht Dir und Deiner Familie gut. War der Internationale Morphologenkongress ein Erfolg? Ich weiß von Marcelo, daß Du ihn dort treffen wolltest.

Liebe Grüße

Dieter

Dear Vera,

I think that the splendid answer by James Hopson, clearly complemented by Moises Escalona, is perfect and actually solve her problem with the lecture.

Wow, I'm really grateful for all your feedback. This wonderful. They will get the best lecture ever on amphibian palaeobiogeography now! I am intrigued by the single species of salamander in the Amazon. Is this a recent arrival?

Crown-group frogs are a Pangean phenomenon. Crown-group caecilians are younger, and are Gondwanan with recent spreads from South to Central America and from India to Indochina; intriguingly, they're absent in Australia and New Zealand – perhaps they're specifically tropical + subtropical Gondwanan and never crossed Antarctica. Crown-group salamanders, and indeed total-group salamanders, are also younger, and are Laurasian with only three exceptions: 1) very recently a few salamandrids have made it to the north coast of Africa; 2) less recently, tiny arboreal bolitoglossine plethodontids have been experiencing an evolutionary radiation in the rainforest of Central and, in the last few million years, South America, where other salamanders continue to be absent; 3) there are intriguing large sirenid-like vertebrae in the Late Cretaceous of Sudan (Kababisha) and Peru (Noterpeton). In short, while the fossil record isn't good enough to give a really definitive answer, salamanders almost certainly never reached Australia.

We asked the same question for the Philippines, despite being adjacent to Hainan, Taiwan and Ryukyus which harbours indigenous species of Order Caudata, mostly Hynobiids. Apparently, Kanto's (Neo-Wallace) line marked the southern limits of subtropical Asian Salamanders, unable to colonise tropical Lanyu and Philippines. In close proximity to Taiwan, the Batanes and Babuyan group of islands are both depauperate of Amphibia to provide substantial comparison of biogeographic affinities. Nonetheless, Australia is fortunate to have many frogs under family Hyliide, which was skipped in South-East Asia, but occurs in Eurasia.

I haven't looked at other possible responses, but we did once have reassurance from Rocek that vertebrae we recovered from an Early Eocene deposit in southeastern Queensland, part of the Tingamarra Local Fauna, were from salamanders. His first reaction was that if the vertebrae had been found in Europe, he would have had no trouble putting them in known genera. However, that was some years ago and, as far as I know, there has been no follow-up. I suppose it's possible they actually belonged to anurans that had somehow developed vertebral structures that converged on those of salamanders, so the mystery remains.

That is awesome Mehmet, thanks :-)!

Yes Michael, with reference to possible Caudate characteristics of Australian fossil vertebrates, we can never underestimate the power of convergence. Who would have guessed that our Australian desert frogs, with so many physical and physiological adaptations similar to their desert counterparts in North America and elswhere, actually have no intercontinental desert frog ancestry. Rather it is now apparent that they redeveloped those necessary characteristics much more recently than those Gondwana land-bridge migrations previously thought to explain them. (ps. I am no longer with NSW Health)

I don't have a thing to add except that you all have provided a really good example of how RG can develop our intellectual camaraderie - each person contributing what she/he knows to produce a nice structure for understanding and hopefully linking our knowledge. Congratulations on this thread!