What Aspidites really are...

PatrickT · 04-20-15, 12:05 PM

I get my Woma python in the next days and would like to debate a bit about the cladisitic of their genus Aspidites.

Only two species are in this genus: the Woma and the blackheaded python. Both are living only in australia and have many unique characteristics. They lack heatpits and their entire body looks different to any other python species. Infact genetic analysis shows that they are not really related to the python genera, they are just put there because they don´t fit anywhere else.

So what are they? It is very possible that they belong to an ancient genus called Madtsoniidae. Some of the most famous snake fossils like Sanajeh belong to this genus. It was once spread over the entire globe. Fossils are known from the middle creatacious. They went extinct in most parts of the world roughly 50 million years ago but did hold out in Australia. The last known extinct of this genus was the Wonambi species, which the Aboriginies still know.

No further studies were done regarding this but it is very possible that the Woma and Blackheaded python both belong to the Madtsoniidae. That would mean they are not just not pythons but not even in the super order Boidae at all.

eminart · 04-20-15, 01:35 PM

Very interesting. I did not know this. I do know that both species are beautiful snakes that are on my "I'd like to have one list".

Derek Roddy · 04-20-15, 01:48 PM

Actually both Womas and BHPs do have a heat pit under their rostral scale.Many of us who have kept Womas and BHPs for years already knew this as they are VERY receptive to temp changes. It was proven several years ago by biologist in Australia when tissue sampling was done on both species.

I will also say that there has been a "small scientific movement" to move the Woma and BHPs out of the python genius all together because of the differences in their genetic code, behavior, etc.

They're a great species and nothing else like em. If anything, the closet I've personally kept has been an indigo snake....without the stinky mess. haha.

D

PatrickT · 04-20-15, 01:53 PM

Quote:

Originally Posted by Derek Roddy

Actually both Womas and BHPs do have a heat pit under their rostral scale.Many of us who have kept Womas and BHPs for years already knew this as they are VERY receptive to temp changes. It was proven several years ago by biologist in Australia when tissue sampling was done on both species.

I will also say that there has been a "small scientific movement" to move the Woma and BHPs out of the python genius all together because of the differences in their genetic code, behavior, etc.

They're a great species and nothing else like em. If anything, the closet I've personally kept has been an indigo snake....without the stinky mess. haha.

D

What the two Aspidites species have can´t be really called a "heat pit" in the classical stance. Its like some primordial form of it and consists from temperature sensitive tissue under the rostral scale as you said yourself. Its morphological completly different to the ehat pits we know from Boas, pythons and vipers.

Aspidites are an incredible amazing group of snakes and it would be amazing if more research could be done to bring some light in their relationship with other species. Its obvious they aren´t pythons in any way.

RAD House · 04-20-15, 02:40 PM

This is very interesting. Is it a primordial form or just an example of convergent evolution? By saying it is primordial you are implying that the ancestors of both groups had a system similar to the Aspidites, but this evolved into something more complex in Boidea. If the two organs are in fact so different I would more likely think it is an example of convergent evolution, which more supports your idea of being two separate families. Proving them to be part of an extinct family may be rather difficult unless you have preserved DNA or full skeletal remains from species with in said family.

PatrickT · 04-20-15, 02:51 PM

Quote:

Originally Posted by MesoCorney

This is very interesting. Is it a primordial form or just an example of convergent evolution? By saying it is primordial you are implying that the ancestors of both groups had a system similar to the Aspidites, but this evolved into something more complex in Boidea. If the two organs are in fact so different I would more likely think it is an example of convergent evolution, which more supports your idea of being two separate families. Proving them to be part of an extinct family may be rather difficult unless you have preserved DNA or full skeletal remains from species with in said family.

Its hard to say. Aspidites definitly have heat "sensor" under their rostral. But its completly different to the heat pits we know from pythons. It could be the primordiwl form of those pits or simply convergent evolution. The problem is that most snake fossils are very fragmented. So it would be hard to prove. All we know so far is that they are not really Pythons at all from an genetic point of view.

RAD House · 04-20-15, 03:01 PM

I was never that interested in BHPs or womas, but I am a sucker for living fossils and Lazarus taxon. Hmm I might need to add these guys to the list.

Albert Clark · 04-20-15, 03:13 PM

Thanks to all of you, Patrick, Derek and Meso for sharing all of that information. I definitely had no clue about this.......

Derek Roddy · 04-20-15, 04:13 PM

Quote:

Originally Posted by PatrickT

What the two Aspidites species have can´t be really called a "heat pit" in the classical stance.

Actually, that's exactly what it is. It's exactly the same as any other python or boa species. It's very apparent when you hold one and see in person. But, from a bio level, they are exactly the same.

Cheers,
D

Derek Roddy · 04-20-15, 04:19 PM

Here's an example

D

shaunyboy · 04-22-15, 06:37 AM

interesting thread folks

cheers shaun

MDT · 04-22-15, 07:42 AM

Not sure if this adds anything, it's an older study...but I saw this about a week ago...Python phylogenetics: inference from morphology and mitochondrial DNA - RAWLINGS - 2008 - Biological Journal of the Linnean Society - Wiley Online Library

Kinda gives some info on the research...mitochondrial DNA analysis..
I give this thread about 1 page before Hoser jumps in and calls us trolls and tells us how stupid we are.

And, to echo Shaun..This is an interesting thread.

SoPhilly · 04-22-15, 08:45 AM

Interesting... so this study is saying that the rostral heat pit was maybe a reversal back to a more primitive form (than the typical heat pits we usually think of) that may have happened as they started burrowing. So - to keep dirt out better, they hid them under their little shovel noses(lol

)? Am I reading this right?

Also, can some one more biology conversant explain what "the genus Aspidites is embedded among the Australo-Papuan genera." means? Not sure what the use of "embedded" signifies in this context.

MDT · 04-22-15, 09:17 AM

that was kinda my take as well. however....i didn't pay for the whole paper. just reading form the abstract.

prairiepanda · 04-22-15, 11:51 AM

My school library has access to that paper. It's pretty long, so I didn't go into great depth reading it, but according to the genetic evidence Aspidites most likely evolved after Python and branched from species with "normal" heat pits. So yes, the rostral heat pit is a result of convergent evolution and not a remnant from their more primitive ancestors.