# Classifying Vertebrates

**URL:** <https://boards.straightdope.com/t/classifying-vertebrates/715725>\
**Category:** In My Humble Opinion\
**Created:** [March 22, 2015, 11:43pm UTC](https://boards.straightdope.com/t/classifying-vertebrates/715725 "2015-03-22T23:43:02Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\
**Post date:** [March 22, 2015, 11:43pm UTC](https://boards.straightdope.com/t/classifying-vertebrates/715725/1 "2015-03-22T23:43:02Z")

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Presently we have birds, mammals, reptiles and amphibians. What changes would be required to add an additional group? Are there any exhisting vertebrates that seem to be close to needing and additional classification? Very hard to imagine anything new appearing.

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**Author:** ![chrisk](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@chrisk](https://boards.straightdope.com/u/chrisk)\
**Post date:** [March 22, 2015, 11:45pm UTC](https://boards.straightdope.com/t/classifying-vertebrates/715725/2 "2015-03-22T23:45:22Z")

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Well, they’re not new, but many fish are also vertebrates. 😉

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**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\
**Post date:** [March 22, 2015, 11:50pm UTC](https://boards.straightdope.com/t/classifying-vertebrates/715725/3 "2015-03-22T23:50:13Z")

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> [@chrisk](#):
>
> Well, they’re not new, but many fish are also vertebrates. 😉

I left fish out, but is anything new imaginable at this point?

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**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\
**Post date:** [March 23, 2015, 1:17am UTC](https://boards.straightdope.com/t/classifying-vertebrates/715725/4 "2015-03-23T01:17:21Z")

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Something microscopic, maybe? Or some extremophile in a sulphur pit?

But as far as megafauna, really unlikely. There aren’t sufficiently large undiscovered habitats.

It’d take something like Pellucidar for it to work.

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**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\
**Post date:** [March 23, 2015, 9:51am UTC](https://boards.straightdope.com/t/classifying-vertebrates/715725/5 "2015-03-23T09:51:26Z")

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> [@HoneyBadgerDC](#):
>
> Presently we have birds, mammals, reptiles and amphibians. What changes would be required to add an additional group? Are there any exhisting vertebrates that seem to be close to needing and additional classification? Very hard to imagine anything new appearing.

Reptilia could conceivably be way better organized. Chelonians, for instance, should really be their own group, snakes and lizards another one, crocodilians a third and birds a fourth…and that’s just the extant groups. Either that or Aves gets collapsed into Reptilia and we _lose_ a group.

That and “fishes” is not one group. Either we’re _all_ fishes, or you should be splitting the 3 or 4 major non-tetrapod groups up better, distinguishing the jawless, cartilaginous and bony-but-not-tetrapod fish as the extant classes (it gets funkier with extinct fish) at least on a level with the terrestrial groups.

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**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\
**Post date:** [March 23, 2015, 11:06am UTC](https://boards.straightdope.com/t/classifying-vertebrates/715725/6 "2015-03-23T11:06:49Z")

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> [@MrDibble](#):
>
> Reptilia could conceivably be way better organized. Chelonians, for instance, should really be their own group, snakes and lizards another one, crocodilians a third and birds a fourth…and that’s just the extant groups. Either that or Aves gets collapsed into Reptilia and we _lose_ a group.

Not only that, but crocodilians are more closely related to birds than they are to snakes or turtles. There is no scientific reason to separate birds from other reptiles.