Re: [dinosaur] Dinosaurs most likely to survive the K-Pg extinction

[Mike Taylor <sauropoda@gmail.com>]

My bad â thanks for putting me straight, Tom!

-- Mike.

On Thu, 13 Aug 2020 at 13:10, Thomas Richard Holtz <tholtz@umd.edu> wrote:
>
> I strongly disagree with Mike on this, though. Not the luck part, which is a 
> big factor, but on the lack of a pattern.
>
> In the terrestrial pattern the size pattern is extraordinarily strong. 
> Animals >5 kg simply did not survive. Even within turtles and crocodilians 
> this is true: large crocs and large tortoise mimics (such as 
> xinjiangchelyids) did not make it.
>
> Within the marine realm planktonic taxa and animals that fed more directly on 
> the plankton die off at rates higher than bottom-feeding benthic organisms. 
> Large pelagic forms die off at rates higher than small demersal forms. And so 
> on.
>
> That said, once you are past these filters who lived and who died among the 
> rest seems to be more stochastic. So why Aves and not Enantiornithes? Why 
> some mammal clades and not others? These are less certain, and probably does 
> have a lot to do about luck.
>
> On Thu, Aug 13, 2020 at 6:57 AM Mike Taylor <sauropoda@gmail.com> wrote:
>>
>> The thing about the K-T extinction is that there is no real pattern to
>> what did and did not survive. Lots of indicators have been proposed:
>> land vs. water-dwelling, large vs. small, endothermic vs. ectothermic,
>> etc. But none of them fits the data, which suggests that the strongest
>> factor affecting survival was sheer dumb luck.
>>
>> So it's not really possible to answer your question of which dinosaurs
>> were most likely to survive that event, beyond the obvious observation
>> that birds evidently did (as you noticed). It could just as easily
>> have been hadrosaurs or titanosaurs; and the surviving mammals could
>> easily have not included the lineage that led to us.
>>
>> -- Mike.
>>
>> On Thu, 13 Aug 2020 at 08:45, Poekilopleuron <dinosaurtom2015@seznam.cz> 
>> wrote:
>> >
>> > Good day to all listmembers! I would like to ask, which non-avian dinosaur 
>> > species from the terminal Cretaceous are (according to you) most likely to 
>> > survive the extinction 66 million years ago? Small bird like species? 
>> > Specialised aquatic or burrowing forms? Are there any hints of favourable 
>> > adaptations for the possible survival in the fossil record? Thank you for 
>> > your opinions! Tom
>
>
>
> --
>
> Thomas R. Holtz, Jr.
> Email: tholtz@umd.edu         Phone: 301-405-4084
> Principal Lecturer, Vertebrate Paleontology
>
> Office: Geology 4106, 8000 Regents Dr., College Park MD 20742
>
> Dept. of Geology, University of Maryland
> https://urldefense.com/v3/__http://www.geol.umd.edu/*tholtz/__;fg!!LIr3w8kk_Xxm!_R8uQMMClnP_Brxru6DtJLgduiFOht3yj70kl1OhgB9M2n86mKuHs2jHnybGULjt$
>  
>
> Phone: 301-405-6965
> Fax: 301-314-9661
>
> Faculty Director, Science & Global Change Program, College Park Scholars
>
> Office: Centreville 1216, 4243 Valley Dr., College Park MD 20742
> https://urldefense.com/v3/__http://www.geol.umd.edu/sgc__;!!LIr3w8kk_Xxm!_R8uQMMClnP_Brxru6DtJLgduiFOht3yj70kl1OhgB9M2n86mKuHs2jHn9C8LhRD$
>  
> Fax: 301-314-9843
>
> Mailing Address:        Thomas R. Holtz, Jr.
>                         Department of Geology
>                         Building 237, Room 1117
>
>                         8000 Regents Drive
>                         University of Maryland
>                         College Park, MD 20742-4211 USA