Monday, 11 January 2021

Pregnant Megaladons - Avoid!

Pregnant Megalodons - Avoid!

If you can't find a scary dinosaur story a scary Megalodon story is almost as good! 

The source is THIS ARTICLE, referencing this ACADEMIC ARTICLE

Megalodons are extinct (thank goodness!) predatory sharks which grew up to 14 metres and died out about 3.6 million years ago. Being sharks, fossils are hard to come by as their skeleton is largely cartilaginous. But some parts can be mineralised and therefore preserved. Teeth (17cm.!) get a lot of attention but it is the spine which is the focus of the paper.

The vertebrae come from a specimen found in Belgium. X-ray scanning of the vertebrae revealed the internal structure and showed it to have growth rings, presumed to be annual. If so the beast died when it was 46 years old and was 9.21 metres long. The academic article details how this was worked out.

But what is fascinating is that it was 2 metres long at birth! And how did it get to be so big - by eating its siblings in the womb! It could not have been an easy pregnancy for the mother! (I may be projecting human values onto a shark in the last sentence. It was probably entirely normal for Megalodon mummies.)

Examples of examined vertebrae of Otodus megalodon (IRSNB P 9893). (a) One of the largest vertebrae (‘centrum #1ʹ) in IRSNB P 9893 (scale bar = 10 cm; photograph courtesy of IRSNB). (b) Computed tomographic image showing sagittal cross-sectional view of vertebra depicted in (a) (scale bar = 5 cm). (c) Computed tomographic image of sagittal cross-sectional view the largest vertebrae (‘centrum #4ʹ) in IRSNB P 9893 showing incremental grown bands presumably formed annually (* = centre of vertebra; scale bar = 1 cm)

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