What's black and blue and red all over?

[BROWNS]

Looks ugly now but could well be going through a colour change and i doubt it will look like it does here as an adult.

Gtp's ad Emerald tree boas are a perfect example of parrallel evoulution...

 

[Morelia_Hunter]

Its probably starting its its colour cahange. Was probably a very dark coloured hatchling. They look like that when they start changing. Fantastic looking snake though!!!!

 

[Jason]

im sure it will look great when its done changing colour, but i would still prfer to get a yellow or red one as a hatchy cause they don't look that bad before changing

 

[Hickson]

cheers for that hix. i always get di and con mixed up... mainly because i consider one to be the other and visa versa.

from my understanding they were both once the same species on gondwana/pangea what u want to call it... when land masses separated they evolved separately to each other to fill "similar" niches, hence similar phenotype but different method of reproduction.

i may be way off but i think some part of that^ is right. fill me in if it isnt

There's not a lot of info on snake evolution, because snakes don't fossilize well so paleontological texts tend to deal more with mammals and fish. And most texts I've got deal with stuff in Australia (predominantly Riversleigh). But from what little I can find I can say the following:

The first reptiles were egglayers (evolving from amphibians) and the development of a hard eggshell meant they were no longer dependent upon water for breeding - therefore they could disperse onto the land and the myriad of habitats. This occured during the Carboniferous period, about 330 million years ago (mya).

The reptiles evolved rapidly and dispersed widely. Dinosaurs first appeared approx 230 mya (Triassic) and survived until 65 million years ago.

One of the earliest snake fossils found has been named Lapparentophis defrenni and was found in the Sahara. It existed during the Early Cretaceous around 130mya. It's thought to be a boid, as they are considered to be the most ancient of the snakes (venom evolving only 15 to 20 million years ago). But it wasn't until the paleocene (when the dinosaurs had become extinct) that the snakes and lizards began to rapidly radiate into many species.

Sometime after Sth America separated from the other Gondwanan continents, some of the Sth American snakes turned to viviparity (giving birth to live young). We come to that conclusion because all boas (which are live bearers) are only found in the Americas. It's been sugested that viviparity may evolve as an adaptive response to cooler climates with correspondingly cooler - and more fluctuating - temperatures.

The boids in Australia and the rest of the world remained egglayers and are what are refered to today as pythons.

I hope that's as clear as mud.



Hix

 

[NCHERPS]

Sometime after Sth America separated from the other Gondwanan continents, some of the Sth American snakes turned to viviparity (giving birth to live young). We come to that conclusion because all boas (which are live bearers) are only found in the Americas. It's been sugested that viviparity may evolve as an adaptive response to cooler climates with correspondingly cooler - and more fluctuating - temperatures.

The boids in Australia and the rest of the world remained egglayers and are what are refered to today as pythons.

I hope that's as clear as mud.



Hix

Hey Hix, Can I just pick up on something there.
Boa's are not just found in the America's, they are found in various African countries and also in NG and pacific islands.

Neil

 

[Hickson]

Neil,

You're quite right. It was late last night when I typed that and I was half asleep. In fact, after typing "clear as mud" I was going to mention the exceptions but I dozed off before submitting and then found I'd been logged out!

Because they're found on islands, it's long been thought that Candoia dispersed from Sth America across the Pacific on islands, and the other species in a similar fashion towards Africa (not gonna theorize on why they're on Madagascar and not the mainland). However, recent genetic evidence suggests that may not be the case for Candoia (see Austin, C.C., 2000, Molecular Phylogeny and Historical Biogeography of Pacific Island Boas (Candoia), Copeia 2000 No.2, pp 341-352).

I was wrong in saying "all boas are only found in the Americas". I should have said "all boas are thought to have originated in the Americas". Thanks for keeping me honest Neil!

Interestingly, Peter Harlow (now at Taronga Zoo) co-authored a paper on Candoia reproduction with Rick Shine some years ago - Peter's the guest speaker at the next Macarthur Herp Society meeting so anyone interested can come along and ask him questions.



Hix