Jump to content

All Activity

This stream auto-updates

  1. Past hour
  2. DPS Ammonite

    Shellfish fossil?

    Please correct name of Arizona city.
  3. Emileecarton

    Tooth from Big brook

    Definitely horse
  4. DPS Ammonite

    Canyon Diablo metiorite?

    Please correct the spelling of meteorite in the title and tags. Otherwise, searching for meteorite is much less likely to bring up your post.
  5. ThePhysicist

    Ptychodus is a lamniform

    BTW I can PM the article if anyone is interested. Ya would be curious to see, but with how complete these are, I doubt a phylogenetic analysis will produce much different results. I'm wanting to understand the algorithms behind these trees - this was done via parsimony, but another method (that may subvert it) is a Bayesian approach which utilizes a similar class of algorithm we use in gravitational-wave astronomy. Interesting thought that might be worth pursuing, I would think convergence is more likely, similar to molariform posteriors in the bonnethead. The diversity of tooth forms within the genus might suggest a diversity of trophic roles? After all we're only seeing the form of one species. A modern analogue might be Carcharhinus which occupy both reefs and the open ocean, so maybe some species of Ptychodus indeed may have specialized on benthic prey.
  6. Today
  7. Jared C

    Ptychodus is a lamniform

    or maybe you? Dentistry while doing paleo research at the side doesn't sound like a bad gig to me. I definitely think you're cut out for some shark research if you ever decided to mess with that
  8. ThePhysicist

    Canyon Diablo metiorite?

    IMO it looks to be unlikely that these are meteorites, but here are a couple of at-home tests that might tell us something: 1. Do these stick very strongly to a magnet? 2. Scrape the rocks on unglazed ceramic, as on the underside of a plate or coffee mug. What is the color left behind?
  9. M3gal0don_M4n

    Dinosaur vertebra?

    Just rocks.
  10. M3gal0don_M4n

    Is this a fossilised bone?

    Okay, thank you!
  11. M3gal0don_M4n

    Shark tooth id?

    I did some searching. I believe it is Carcharodon hastalis?
  12. JD1969

    Canyon Diablo metiorite?

    Really hard to get a good pic with that reflective surface. The first one I polished one side and it came out like a mirror almost. The others went through the tumbler. Definitely not desert varnish!
  13. FranzBernhard

    Canyon Diablo metiorite?

    Some of those could be ventifacts with desert varnish? Unable to judge on the "base rock". Franz Bernhard
  14. M3gal0don_M4n

    Anybody know what this is?

    Definitely a tooth of some kind? I agree with the others, probably a Dolphin tooth.
  15. M3gal0don_M4n

    Shark tooth id?

    I found this shark tooth in a store. I believe it to be a Mako? My only photo. I have been here a lot, and it has been here the whole time.
  16. JD1969

    Canyon Diablo metiorite?

    The first 3 are of the original post pic. The last 3 are of other pieces I found like it in close proximity in northern Arizona.
  17. Jaybot

    Ptychodus is a lamniform

    Wow! Being a fan of Ptychodus sharks, this is very interesting. Thank you so much for sharing!
  18. JD1969

    Canyon Diablo metiorite?

    I have this one.
  19. TRexEliot

    JUST A ROCK ??

    There were more pictures originally, if I'm not mistaken. Either that or my phone was glitching.
  20. Jared C

    Ptychodus is a lamniform

    Holy ####! Bombshell indeed. Mexico has some incredible Cretaceous lagerstätten that I feel will get international attention in next couple decades, as it absolutely should. The paleontology of the country is very underrated. Can't wait to see what our southern neighbors continue to discover
  21. Still a cool piece to add to the collection! How come my local thrift stores never have cool things like that?
  22. Fossildude19

    Shark's Tooth? Or something different?

    Agreed - Sea robin skull.
  23. Thanks for the information. So it is a fossil but essentially a paperweight?
  1. Load more activity
×
×
  • Create New...