Balegem shark teeth

[Max-fossils]

Hi all!

 

Here are three sharkteeth I have from Balegem, Belgium. The sharkteeth there are from the Eocene. Those will soon go into a trade, so I need to get an ID quickly!

Right now, the ID I have is this (from left to right):

Physogaleus latus, Lamna nasus, Jaekelotodus trigonalis.

Are those ID correct?

 

Best regards,

 

Max

[MarcoSr]

Tooth 1    Looks more like the genus Abdounia.  Need to see a better picture of the serrations but looks like A. recticona versus A. beaugei.

Tooth 2   Lamna nasus is an extant species.  For the time period looks more like Isurolamna, maybe I. inflata.  EDIT  The more that I look at the root features of this tooth and the cusplets the less that I think it is Isurolamna.  Need better pictures but tooth could be an upper A3 of Brachycarcharias lerichei .

Tooth 3  Looks like genus Jaekelotodus. 

 

 

Marco Sr.

Edited February 4, 2017 by MarcoSr
add another possibility

[Max-fossils]

3 hours ago, MarcoSr said:

Tooth 1    Looks more like the genus Abdounia.  Need to see a better picture of the serrations but looks like A. recticona versus A. beaugei.

Tooth 2   Lamna nasus is an extant species.  For the time period looks more like Isurolamna, maybe I. inflata.  EDIT  The more that I look at the root features of this tooth and the cusplets the less that I think it is Isurolamna.  Need better pictures but tooth could be an upper A3 of Brachycarcharias lerichei .

Tooth 3  Looks like genus Jaekelotodus. 

 

 

Marco Sr.

Hi Marco,

 

Thanks for the help!

For tooth 1 I agree with Abdounia beaugei. Tooth 2 does look a bit like Isurolamna affinis (more than inflata); and Brachycarcharias lerichei does seem like the match. So for 3 you would agree with my guess of Jaekelotodus trigonalis?

 

Here are some closeups of the A. beaugei (first 4) and the B. lerichei (last 4).

 

Best regards,

 

Max

[Max-fossils]

[Max-fossils]

[Max-fossils]

[sixgill pete]

I believe the first tooth is Abdounia recticona, not A. beaugei as Marco suspected. I agree with Marco on the second likely being Brachycarcharias lerichei. As far as the third, I agree with Jaekelotodus sp. as far as species, I think the wear on the tooth may prevent this.

[Max-fossils]

48 minutes ago, sixgill pete said:

I believe the first tooth is Abdounia recticona, not A. beaugei as Marco suspected. I agree with Marco on the second likely being Brachycarcharias lerichei. As far as the third, I agree with Jaekelotodus sp. as far as species, I think the wear on the tooth may prevent this.

Alright, thanks for the help!

[MarcoSr]

1 hour ago, Max-fossils said:

Hi Marco,

 

Thanks for the help!

For tooth 1 I agree with Abdounia beaugei. Tooth 2 does look a bit like Isurolamna affinis (more than inflata); and Brachycarcharias lerichei does seem like the match. So for 3 you would agree with my guess of Jaekelotodus trigonalis?

 

Here are some closeups of the A. beaugei (first 4) and the B. lerichei (last 4).

 

Best regards,

 

Max

 

 

 

Max

 

What makes the id of your teeth more difficult for me is that I’m familiar with the faunas from the US and what the researchers id the US teeth as.  I’m not as familiar (Although I have searched matrix from a number of European sites) with the European faunas like Balegem.  The starting point for an id should be the list of described shark species from the fauna.  That doesn’t mean that what you have isn’t something new but you should first see if it matches a species already described from the fauna.

 

The id for the US Paleocene and Eocene Isurolamna teeth has not showed a clear distinction for me between affinis and inflata.  Cappetta suggested that affinis probably branched from inflata (Cappetta 1987) and implied that both affinis and inflata co-existed in the Paleocene or Early Eocene.  The US Eocene Isurolamna teeth that I’m familiar with are identified by most researchers now as inflata. I was comparing your teeth with what I see in the US.  But bottom line, the tooth features based upon the teeth that I see in the US better match an upper A3 of Brachycarcharias lerichei than the Isurolamna teeth that I see from the US.

 

I see a lot of A. beaugei in the Paleocene and early Eocene of the US.  As the Eocene gets younger I start to see A. recticona.  So the age of the formation can help distinguish the two species if in doubt in my mind.  The problem for me with your tooth is that in the US A. beaugei can have from 0 to 3 cusplets (my observation) on a side and A. recticona can have 3 to 8 cusplets on a side (A. recticona recticona usually 3 or 4 and A. recticona claibornensis usually 5 to 8 cusplets).  However, US researchers typically state that A. beaugei has only 1 or two cusplets on a side.  So if you use that criteria your tooth wouldn’t be A. beaugei.  However like I said I have a good number of what I believe are A. beaugei with 3 cusplets on a side.  The A. recticona that I see usually see have a different upward angle on the first cusplet and that first cusplet looks noticeably bigger in the series of cusplets.  I would use whatever your researchers use as an id from the Balegem fauna.

 

In the US the Jaekelotodus teeth that I’m familiar with are identified as Jaekelotodus robustus (LERICHE, 1921).  Your tooth is very similar to the US Eocene teeth that I see.  However I see very similar teeth from Europe called Jaekelotodus trigonalis.  I would use whatever your researchers use as an id from the Balegem fauna.

 

Marco Sr.

[Max-fossils]

15 hours ago, MarcoSr said:

The problem for me with your tooth is that in the US A. beaugei can have from 0 to 3 cusplets (my observation) on a side and A. recticona can have 3 to 8 cusplets on a side

Thanks for all the help!

So I'll put the teeth as such: Abdounia reticona, Brachycarcharias lerichei. But for the last one: Jaekelotodus robustus or Jaekelotodus triginalis? Both are found at Balegem.

Here is a list of the different shark species discovered at Balegem (Lutetian stage, Eocene --> 40 - 49 mya):

• Abdounia reticona
• Brachycarcharias lerichei
• Carcharias cf. acutissima
• Galeocerdo latidens
• Hypotodus verticalis
• Jaekelotodus robustus

• Jaekelotodus trigonalis

• Otodus auriculatus

• Striatolamia macrota

• Xiphodolamia ensis

Best regards,

 

Max

[MarcoSr]

4 hours ago, Max-fossils said:

Thanks for all the help!

So I'll put the teeth as such: Abdounia reticona, Brachycarcharias lerichei. But for the last one: Jaekelotodus robustus or Jaekelotodus triginalis? Both are found at Balegem.

Here is a list of the different shark species discovered at Balegem (Lutetian stage, Eocene --> 40 - 49 mya):

• Abdounia reticona
• Brachycarcharias lerichei
• Carcharias cf. acutissima
• Galeocerdo latidens
• Hypotodus verticalis
• Jaekelotodus robustus

• Jaekelotodus trigonalis

• Otodus auriculatus

• Striatolamia macrota

• Xiphodolamia ensis

Best regards,

 

Max

 

Max

 

I agree with your id of the first two teeth.

 

Your third tooth is a lateral.  It looks like a Jaekelotodus robustus to me.  The laterals of Jaekelotodus trigonalis have crowns that are more triangular and more upright (rather than curved) than your specimen.

 

Marco Sr. 

[Max-fossils]

2 hours ago, MarcoSr said:

 

Max

 

I agree with your id of the first two teeth.

 

Your third tooth is a lateral.  It looks like a Jaekelotodus robustus to me.  The laterals of Jaekelotodus trigonalis have crowns that are more triangular and more upright (rather than curved) than your specimen.

 

Marco Sr. 

 

 

Alright, thanks so much!

I feel more confident doing the trade now that I know the correct species I will be sending! 

 

Best regards,

 

Max