[continued from previous message]   
      
   >>>>>>>>  > they were weasel like ancestral carnivores, so my guess is   
   >>>>>>>> that they   
   >>>>>>>>  > could have reevolved claws to be more arboreal.   
   >>>>>>>>   
   >>>>>>>> Where do you get this figure of 30 million years?   
   >>>>>>>>   
   >>>>>>> The common ancestor of extant carnivores existed around 55   
   >>>>>>> million years ago, and that is around 30 million years after that   
   >>>>>>> common ancestor's lineage split off from the horse lineage.   
   >>>>>>> Plenty of time to reevolve claws.   
   >>>>>>   
   >>>>>> The relevant clawed clade is Ferae, not Carnivora. (To the best of   
   >>>>>> my knowledge miacids are not hooved; viverravids are not hooved;   
   >>>>>> oxyaenids are not hooved; hyaenodonts are not hooved; pangolins   
   >>>>>> are not hooved; and pantolestids are not hooved.) The consensus   
   >>>>>> date for Ferae is 65 million years ago. Wikipedia gives a date for   
   >>>>>> 73-85 million years for Scrotifera, but the relevant nodes,   
   >>>>>> depending on topology, are Zooamata or Ferungulata, which are   
   >>>>>> younger.   
   >>>>>>   
   >>>>>> As support for hooves as a convergent trait, not all mesonychians   
   >>>>>> (which are stem artiodactyls) possessed hooves. However there is   
   >>>>>> dispute whether the hoofless mesonychians (arctocyonids) are stem-   
   >>>>>> artiodactyls.   
   >>>>>   
   >>>>> It's also the case that not all (or any??) stem-perissodactyls are   
   >>>>> hooved, and even some crown-perissodactyls aren't (chalicotheres).   
   >>>>> I'd say that convergence in hoofiness is considerably more   
   >>>>> parsimonious given the data, even forgetting about Dollo's Law.   
   >>>>>   
   >>>>   
   >>>> I believe that notoungulates and litopterns are hoofed stem-   
   >>>> perissodactyls. If chalicotheres are primitively clawed, this   
   >>>> requires convergence in Hippomorpha, Ceratomorpha, Notoungulata/   
   >>>> Litopterna, and possibly other groups.   
   >>>>   
   >>> It's also possible that chalicothere claws, which actually are a bit   
   >>> weird-looking, are a real example of a reversal. I'm also wondering   
   >>> what Ambulocetus, etc., digits look like.   
   >>>   
   >>   
   >> The article that I read claimed that Ambulocetus had the bones at the   
   >> tip of it's toes are slightly flattened on top indicating that it had   
   >> hooves, but the bones did not show the widening that would indicate   
   >> some type of substantial hoof.  I can't recall exactly, but they might   
   >> have called them some type of fingernail like hoof.   
   >   
   > See? And all without needing a mummy.   
      
   They couldn't say the same thing about pakecetus toe bones.  They   
   claimed that pakecetus had claw like hooves, probably, because the toes   
   looked like they had claws.   
      
   Ron Okimoto>   
      
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