CADOCHAMOUSSETIA SUBPATRUUS

Cadochamoussetia subpatruus (Nikitin 1885)

I have a thing for chunky ammonites and find their inflated shapes very pleasing. 

This lovely chunky macroconch is the female of the species Cadochamoussetia subpatruus (Nikitin 1885). 

She hails from the Middle Jurassic, Lower Callovian, Elatmae zone, Subpatruus subzone in a clay mining quarry near Uzhovka 2, in the Pochinoksky district of Nizhny of the Novgorod region of western Russia. 

This specimen has signs of intravital damage (i.e., damage that did not immediately lead to death) on the edge of her shell. 

We see this type of non-lethal damage recorded on the shells of ammonites and other marine goodies in the fossil record. These telltale bits of evidence for challenges to the species while living are recorded and preserved long before the burial event. We see similar signs of damage on the shells of modern Nautilus. 

These lesions resemble frequently bitten edges. Perhaps damage from predation or the result of bashing up against something solid on the seafloor. There is a wee bit more damage on the mouth of the shell. Where the shell should have stopped growing upon the ammonite reaching puberty, the growth continues for another 5 cm of thinly laminated shell — perhaps signalling physicochemical impact or shortage of resources for the ongoing construction of the usual thickness. This photo is courtesy of the deeply awesome Emil Black.