# Does this Mutation of the Hand Occur? **URL:** \ **Category:** Factual Questions\ **Created:** [May 4, 2006, 7:44pm UTC](https://boards.straightdope.com/t/does-this-mutation-of-the-hand-occur/355439 "2006-05-04T19:44:29Z")\ **Posts on this page:** 4\ **Page:** 2
**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:** [May 5, 2006, 9:34am UTC](https://boards.straightdope.com/t/does-this-mutation-of-the-hand-occur/355439/21 "2006-05-05T09:34:42Z")
> [@Colibri](#): > > As a matter of fact, the Terror Bird [_Titanis walleri_](http://www.phonono.com/titanis_titel.jpg) was enough to give anyone nightmares, even without the clawed forefeet. It stood somewhere between 7 and 9 feet tall, and roamed Florida in the Pleistocene. have they actually found feathers for this? I’m just asking, you know, just in case this “big bird” was yellow all over - they might not be that extinct… BTW, **Colibri** , **Finch** - it’s for stuff like this that I’ll keep re-upping every year. Nice work. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 5, 2006, 3:49pm UTC](https://boards.straightdope.com/t/does-this-mutation-of-the-hand-occur/355439/22 "2006-05-05T15:49:04Z")
> [@John Mace](#): > > Back to my earlier question about mammals… I wasn’t so much interested in ungulants who might have lost some digits, but whether all mammals had the pattern outlined by **Colibri** – if we look at primitive mammals like a platypus, does it have the typical mammlian pattern? Yes. (Offhand I’m not sure if monotremes may not have an additionally reduced formula, but they don’t have the “reptilian” one). Some early members of the lineage that led to mammals had the typical 2.3.4.5.4 “reptilian” pattern. (I am using the word “reptile” loosely here for early amniotes in general). The 2.3.3.3.3 pattern was established in the later therapsid lineages (earlier ones had some of the phalanges on digits III and IV reduced or vestigial). The reduction in phalanges was probably due to the switch from a sprawling to an erect gait in the therapsids. One exception to this phalangeal pattern is in the whales. Like other marine amniotes, they have undergone multiplication of the phalanges to form the flippers. Whales may have up to 13-14 phalanges in some of the digits. Both ichthyosaurs and plesiosaurs also had greatly increased numbers of phalanges; ichtyosaurs also expanded the number of “digits,” with up to 8 phalangeal rows. ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [May 5, 2006, 4:15pm UTC](https://boards.straightdope.com/t/does-this-mutation-of-the-hand-occur/355439/23 "2006-05-05T16:15:02Z")
> [@Colibri](#): > > Both ichthyosaurs and plesiosaurs also had greatly increased numbers of phalanges The same is true for mosasaurs, as well. ---
**Author:** ![Belrix](https://avatars.discourse-cdn.com/v4/letter/b/ed655f/32.png) [@Belrix](https://boards.straightdope.com/u/Belrix)\ **Post date:** [May 5, 2006, 7:40pm UTC](https://boards.straightdope.com/t/does-this-mutation-of-the-hand-occur/355439/24 "2006-05-05T19:40:38Z")
I attended college with a woman who was a mutant\*. Unfortuantely, this wasn’t a mind-control, eyeball-blasting, weather-controlling type of mutation, (which would be wicked cool) but she had physical abnormalities. This was a genetic mutation, rather than a birth defect, because she said she had a family member with the same appearance. Her torso & arms were normal, her legs shortened, ending in a complex joint that seemed to combine the knees & ankles. Her hands, and why I’m posting, were 5-fingered. Not 4 fingers & a thumb but had five fingers. Rather than having the extra finger connect as the thumb does, at a “ball” that lets it cross over the palm, her fifth finger was attached to her palm the same way the other four did. She really didn’t have an opposable digit on each hand as a result, although the flexibilty of the palm seemed to allow a resonable level of control Nice woman, makes me a feel a little guilty I never got to know her better. \*No offense intended - just sounds fun to say “mutant” and simpler than saying “had a genetic mutation”. [Previous page](https://boards.straightdope.com/t/does-this-mutation-of-the-hand-occur/355439.md?page=1)