Ok I Think The Lower Is A Squalodon But The Upper....

[Boesse]

OK, Bmorefossil, I'll try and correct some of the confusion:

Toothed whales - Odontoceti - include (this is not a comprehensive list) the following families:

Physeteridae (sperm whales)

Kogiidae (dwarf sperm whales)

Ziphiidae (beaked whales)

Squalodontidae (shark-toothed whales)

Squalodelphidae (shark-dolphin; no common name)#

Eurhinodelphidae (long-beaked "dolphin")#

Platanistidae (Ganges/Indus river dolphin and extinct relatives)

Pontoporiidae (La Plata river dolphin and extinct relatives)#

Iniidae (Amazon river dolphin and extinct relatives)#

Lipotidae (Yangtze river dolphin and extinct relatives)#

"Kentriodontidae" (primitive delphinoids)*#

Delphinidae (dolphins, orca, pilot whales)*#

Albireonidae (porpoise like dolphins)*#

Monodontidae (beluga, narwhale, and extinct relatives)*

Phocoenidae (porpoises)*#

All taxa with an asterisk * belong to the Delphinoidea, or advanced odontocetes.

All taxa with # are what a lot of people incorrectly refer to as 'porpoises'; these are all relatively small toothed whales, but are not at all closely related. In fact; there are several different superfamilies included under that label - delphinoids, platanistoids, ziphiods...

Here's a cladogram or 'family tree' just to show how distantly related many of these families are: http://www.archaeocete.org/Barnes%20PhylogenySuborder3.jpg

So: Kentriodontids occur worldwide, and are a 'fake' group, because they are not a biologically 'real' group, or clade, because some of their descendants (i.e. all other delphinoids) are excluded from the family Kentriodontidae. Kentriodontids are known from the late Oligocene to the late Miocene from New Zealand, Japan, California, eastern US, and several places in europe. These are not true dolphins, nor are they true porpoises; I usually call these 'kentriodontid dolphins'.

Delphinids occur only in the latest Miocene and Pliocene, and are only found as pre-pleistocene fossils in the atlantic basin, such as at Lee Creek (Yorktown Fm) and Belgium and Italy. Delphinids are true dolphins, and include spinner dolphins, bottlenose (aka flipper), orcas, pilot whales, etc. These are also not porpoises.

Phocoenids are true porpoises, and have a middle Miocene to modern distribution. There are only a handful of true porpoise fossils from the atlantic, and these are all from the Pliocene of Belgium. No phocoenid fossils have yet been reported from the east coast, thus no one on the east coast has actually found anything that can be called a 'porpoise'.

However, porpoises are very common and abundant in Mio-Pliocene sediments of California, Baja California, and Japan; I'm currently researching several fossil phocoenid skulls from central California.

So, in terms of dolphins and porpoises, no true porpoises occur in the chesapeake group, and no true dolphins occur any lower than the Yorktown Formation (and *possibly* the Eastover Formation) on the east coast. All toothed whales from the Chesapeake Group (namely the Calvert Fm.) belong to the Squalodontidae, Platanistidae, Physeteridae, Ziphiidae, Eurhinodelphidae, Pontoporiidae, and the "Kentriodontidae"; thus they all belong to archaic groups.

Let me know if you have any questions - I apologise if I have caused any frustration; its my job to disseminate knowledge about fossil cetaceans, and to delineate the limits of what we can say about fossils (the second part is more or less the job description of a paleontologist).

Bobby

[Guest bmorefossil]

thanks man thats what i was looking for

[Auspex]

Thank you Bobby! :applause:

[Maryland Mike]

Thanks, that's the kind of enlightenment I love to find on this forum.

[Boesse]

Ya, no problem guys. Its my pleasure and my job to disseminate what I've learned, especially to you folks on the east coast, where so many more cetacean fossils are found by collectors.

In any event... I do not mean to be frustrating, but there is only a certain level to which we can identify some fossils. In the case of isolated teeth, vertebrae, ribs, etc., it is often impossible to identify anything past "cetacea". In fact, most 'flipper' (forelimb) bones (even the radius, ulna, and humerus) are often difficult to identify past suborder (i.e. Odontoceti, Mysticeti).

In other words, I should probably just say this:

The only cetacean fossils identifiable to the species level are skulls, period.

The only cetacean fossils identifiable to the genus level are partial skulls, earbones, and sometimes mandibles.

Cetacean fossils that *may* be diagnosable to the family level are the atlas/axis complex, and the humerus/ulna.

I know it is tempting to try and identify everything to the species level (believe me, I've been there), but keep in mind that unless you have at least half a skull, there is no scientific or evidential basis for an identification past the genus level.

Bobby

[Guest bmorefossil]

ok attempt 15..................

[Guest bmorefossil]

ok i got it up! and i must say it is the smallest picture i have ever posted but now with some better connection ill try normal size.

bam!

[makoken]

ok i got it up! and i must say it is the smallest picture i have ever posted but now with some better connection ill try normal size.

bam!

GREAt teeth!!

[Guest bmorefossil]

GREAt teeth!!

thanks, i have only been finding them in the last 2 years, i have been going to a new site and you can find them there

[Guest bmorefossil]

ok what do you guys think about this, i was looking at some peccary tusks and i found this, the tusk is not broken, it just has natural wear patterns.