Otodus body size to vertebrae

[sharkcollector]

Recently, after going to my favorite fossil store, I aquired a Otodus Obliquus vertebrae. It came from a formation in Morocco, and is approximately 54 million years old, from the pliocene. Otodus is an extinct mackerel shark, related to the far larger O. Megalodon. The fossil is approximately 10.5 centimeters or 4.13 inches. I was wondering how large the shark would be relative to this vertebrae (assuming this was the largest vertebrae from the shark.)

 

[ThePhysicist]

Hello, and welcome to the forum!

 

From Dana Ehret's thesis:

"Centrum radius is used because total length (TL) of these sharks [Otodus obliquus, Carcharocles auriculatus, Carcharocles angustidens, and Carcharocles megalodon] is not known. Previous studies of fossil lamniforms (Gottfried et al. 1996; Shimada 1997b; Shimada 2008; Ehret, Hubbell, and MacFadden 2009; Pimiento et al. 2010) have estimated TL of extinct species based on CR or centrum diameter of the extant C. carcharias. While TL regressions may be acceptable for establishing general estimated body lengths, I caution the use of this information in growth studies without a reasonable justification. Furthermore, this study compares growth in fossil megatoothed sharks to C. carcharias specimens from the Indian Ocean previously reported by Wintner and Cliff (1999). Comparisons of growth in megatoothed and white sharks, based solely on TL or precaudal length (PCL) of Carcharodon could misrepresent the fossil data."

https://ufdc.ufl.edu/UFE0042397/00001/pdf

 

If you wish to use regressions from the extant white shark for a ballpark estimate, here's one which would place yours at about 6 m fork length (assuming you measured the diameter):

^ Natanson & Skomal (2014)

 

Edit: Also, your centrum is not from the Pliocene - it's Eocene, likely from the Khouribga phosphates

Edited January 3, 2023 by ThePhysicist

[sharkcollector]

Oh thanks for the information and for your help :).