MarcoSr Posted January 15, 2016 Share Posted January 15, 2016 Here are two jaws that I recently acquired. One jaw, Jaw 1, is 3.5” wide and 2.5” inches high. The other jaw, Jaw 2 is 2.5” wide and 1.625” inches high. They both were sold as Centrophorus granulosus (Gulper Shark) jaws. However, when you see the pictures below, you will see that there is a very noticeable difference in tooth morphology between the jaws. Centrophorus can display both ontogenetic heterodonty and sexual dental heterodonty. One jaw is noticeably bigger than the other so juvenile/adult tooth differences could be what is being seen or possibly male/female differences. Here are the overall jaws: Jaw 1 Jaw 2 To better see tooth details double clique the below pictures. If you mouse over the pictures you will see the file name which has additional positional information. Note that Centrophorus teeth interlock in both the upper and lower jaws and that the lower teeth can be serrated. Upper jaw symphysis: Jaw 1 Jaw 2 Lower jaw symphysis: Jaw 1 Jaw 2 Centrophorus can have both upper jaw and lower jaw medial teeth. Upper jaw medial teeth. Note Jaw 1 has a medial tooth (red) and there are three teeth in the symphysis. Jaw 2 has two teeth in the symphysis and doesn’t appear to have a medial tooth. Jaw 1 Jaw 2 Continued in the next reply: Marco Sr. 2 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
MarcoSr Posted January 15, 2016 Author Share Posted January 15, 2016 Lower jaw symphyseal teeth. Each jaw has a medial tooth (red): Jaw 1 Jaw 2 I have seen individual Centrophorus teeth identified as anterior, antero-lateral, lateral and commissural. I am not going to try to name those positions of the teeth in these two jaws because I do not have adequate reference material to completely distinguish them. Upper jaw extreme left and right side teeth: Jaw 1 Jaw 2 Lower jaw extreme left side teeth: Jaw 1 Jaw 2 Continued in the next reply: Marco Sr. 2 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
MarcoSr Posted January 15, 2016 Author Share Posted January 15, 2016 Lower jaw extreme right side teeth: Jaw 1 Jaw 2 Here are some upper jaw teeth left and right side: Jaw 1 Jaw 2 Continued in the next reply: Marco Sr. 2 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
MarcoSr Posted January 15, 2016 Author Share Posted January 15, 2016 Here are some lower jaw teeth left and right side: Jaw 1 Jaw 2 Here are serrated lower jaw teeth: Jaw 1 Jaw 2 Here are pictures that show the number of rows of teeth in this jaw: Jaw1: I can see at least 6 upper rows of teeth. Jaw2: I can see at least 5 upper rows of teeth. Jaw 1 Jaw 2 Jaw1: I can see 7 rows of lower teeth (note there are two rows on the labial side that don’t show up in this picture). Jaw2: I can see 6 rows of lower teeth (note there is one row on the labial side that doesn’t show up in this picture). Jaw 1 Jaw 2 Jaw 1: The upper jaw has 17 tooth files left and 19 tooth files right of the medial tooth. Jaw 2: The upper jaw has 19 tooth files left and 18 tooth files right of the symphysis. Jaw 1: The lower jaw has 15 tooth files left and 15 tooth files right of the medial tooth. Jaw 2: The lower jaw has 14 tooth files left and 14 tooth files right of the medial tooth. What makes individual tooth identification even more difficult is that there is a species variation which can make another Centrophorus granulosus jaw and teeth slightly different because of shark age, gender, locality etc. To get a complete feel for Centrophorus granulosus jaws and teeth you would really need to look at a lot of different jaws from different localities. Marco Sr. 2 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
SailingAlongToo Posted January 15, 2016 Share Posted January 15, 2016 These are awesome MarcoSr. Thanks for sharing. Don't know much about history Don't know much biology Don't know much about science books......... Sam Cooke - (What A) Wonderful World Link to comment Share on other sites More sharing options...
Auspex Posted January 15, 2016 Share Posted January 15, 2016 It seems that shark tooth morphology is a bit of a rabbit hole to those of us desiring concise ID guidelines... Ma Nature is complicated! "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
ynot Posted January 15, 2016 Share Posted January 15, 2016 Tony Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
MarcoSr Posted January 15, 2016 Author Share Posted January 15, 2016 It seems that shark tooth morphology is a bit of a rabbit hole to those of us desiring concise ID guidelines... Ma Nature is complicated! Chas I fully agree. First extant sharks have been named and described based upon physical characteristics, like size, body shape, fin shape and size, etc. The shark teeth and jaws are a footnote in a lot of the descriptions. So it is extremely difficult to get good reference material on the jaws and teeth of each described species. I have the publications of researchers like Herman, Bass, Garrick, Compagno etc., which even taken all together, have inadequate descriptions and pictures of a good number of extant shark species jaws and teeth. Plus they have not standardized a terminology for what teeth are called so a tooth could be an anterior with one researcher, antero-lateral with another, a lateral with another etc. When I buy a jaw, I don't get the shark's body with it to compare to the species description and what I'm finding unless the species is very common like a mako for instance there really isn't adequate extant teeth and jaw descriptions. Secondly, there can be tremendous variation not only in the teeth of an individual shark because of position in the mouth but when you add in male/female, juvenile/adult, locality differences etc. it is a very daunting task to try to compare an extant jaw to some blurry pictures of one dentition or a hand sketched dentition and even make a positive jaw id to a species. One thing that I learned so far by looking at the extant jaws and from the papers of the shark researchers is how much variation there is within an individual species in the number of teeth in both the upper and lower jaws. So if the number of teeth in the jaws isn't even consistent you can imagine how inconsistent the teeth themselves can be. I believe these two jaws are definitely Centrophorus from tooth dentitions and teeth I have seen in the different papers but have much less confidence in what species they are. Marco Sr. 1 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
MarcoSr Posted January 15, 2016 Author Share Posted January 15, 2016 These are awesome MarcoSr. Thanks for sharing. Tony Thank you. This genus/species has some really interesting teeth that we don't normally see. Marco Sr. "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
ynot Posted January 15, 2016 Share Posted January 15, 2016 Hey-hi Marco, I noticed that these teeth look similar to the teeth from Squalus sp.. Do You know if there is any relation between the two species? Love the new series!! Tony Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
MarcoSr Posted January 15, 2016 Author Share Posted January 15, 2016 Hey-hi Marco, I noticed that these teeth look similar to the teeth from Squalus sp.. Do You know if there is any relation between the two species? Love the new series!! Tony Tony Squalus sp. and Centrophorus granulosus are in the same order Squaliformes. They do have similar looking crowns on the lower teeth. I have several different species of Squalus that I'll photograph and post at some point. Marco Sr. "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
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