Bill Heim

  • 1 day, 21 hours ago
    Bill Heim posted a new activity comment

    Did this come out of Zone-2? It looks like it.

  • 1 day, 21 hours ago
    Bill Heim posted a new activity comment

    Does the tip have a noticeable twist (looking down it). Due to the damage, it is difficult to tell if this is P. contortus or G. aduncus. Ignore that ^@## article saying contortus are lower teeth of aduncus. It is pure BS.

  • 1 day, 22 hours ago
    Bill Heim posted a new activity comment

    Round Mountain Silt member of the Temblor Formation, Kern County

  • 1 day, 22 hours ago
    Bill Heim posted a new activity comment

    Carcharodon carcharias – Great White Shark

  • 1 day, 23 hours ago
    Bill Heim posted a new activity comment

    Yes, Negaprion

  • 6 days, 2 hours ago
    Bill Heim posted an update in the group Shocking Shark Teeth

    Again I am going to pause on the genus Carcharhinus and talk briefly about another shark which is often misidentified.  This is the Tiger Shark (Galeocerdo).  I am always astonished when someone misidentifies a different species tooth as a tiger shark as tiger sharks have very distinctive teeth.  I am not going to go into detail on tiger shark teeth for now for various reasons.  In the tiger shark as there are 2 distinct lineages (the teeth are similar enough to identifying them both as Tiger Sharks).  Additionally there is a couple of other genera which can be confused with tiger shark teeth.  Physogaleus (which can be excused as it was formerly classified as Galeocerdo) and Squalicorax which went extinct at the end of the Cretaceous.  If it is a Cretaceous tooth, it is NOT a tiger shark. So these are tiger shark teeth, the uppers and lowers look just the same.  If it doesn’t look like below, it is not from a tiger shark.



  • 6 days, 2 hours ago
    Bill Heim posted a new activity comment

    It is Hemipristis. It is a contrasty image which washes out detail. You can use any number of image programs to decrease the contrast and/or brighten the image. Windows comes with some, as does Apple and most phones. You can also find free ones on the internet.

  • 1 week ago
    Bill Heim posted a new activity comment

    Common – Extinct Tiger-like Shark, Genus – Physogaleus, Specific Epithet – contortus

  • 1 week ago
    Bill Heim posted a new activity comment

    Genus – Carcharhinus, Specific Epithet – perezii (Caribbean Reef Shark)

  • 1 week ago
    Bill Heim posted a new activity comment

    Parens around the Author means that the genus was changed from the original. Agassiz probably originally described it as Squalus hastalis.

  • 1 week ago
    Bill Heim posted a new activity comment

    This is Carcharodon planus. Related to the Great White shark (a dead end off branch).

  • 1 week ago
    Bill Heim posted a new activity comment

    This is Physogaleus contortus. An extinct tiger like shark. An image of the other side is needed for curation. If you give me permission, I can fill in all the details.

  • 1 week ago
    Bill Heim posted a new activity comment

    Not a lemon shark. This appears to be Carcharhinus plumbeus, sandbar shark. Please use a more contrasting background (lighter), in addition to an image of the other side.

  • 1 week ago
    Bill Heim posted a new activity comment

    Not a thresher shark. This is an upper Carcharhinus species. However due to the wear, it is impossible to tell which one.

  • 1 week ago
    Bill Heim posted a new activity comment

    Aetobatis, Eagle Ray. Rhinoptera bars are not as angular. Also please use a background that contrasts more (lighter) with the teeth.

  • 1 week ago
    Bill Heim posted a new activity comment

    Picture is too unclear and small to tell exactly what genera it is. It doesn’t appear to be a thresher shark. A better, closer image would be helpful. Also use a background that contrasts with the tooth. Grey on grey makes it difficult to produce a clear image.

  • 1 week ago
    Bill Heim posted a new activity comment

    Not a lemon shark. This is an upper tooth of a Carcharhinus species but due to the wear, it is difficult to narrow down exactly which species.

  • 1 week ago
    Bill Heim posted a new activity comment

    Unlike many of the other postings, this actually appears to be a lower Lemon shark tooth (Negaprion) although unusually small. Must have been a very young shark. An image of the other side would help to confirm this. A scale bar (ruler) in the image would help as well.

  • 1 week ago
    Bill Heim posted a new activity comment

    Order Myliobatiformes = stingrays. They have a crushing plate made of rows of bars fit together. The smooth side is top part of the plate (biting part) while the ridged part is the root.

  • 1 week ago
    Bill Heim posted a new activity comment

    Galeocerdo is a tiger shark which have very distinctive teeth. This is not a tiger shark but instead a lower Carcharhinus species. From the lower teeth (which this is), it is usually (there are a few exceptions) to narrow down the exact species. Due to the wide root, it is possibly (possibly) a Sandbar Shark tooth (Carcharhinus plumbeus).

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