Southern Marsh Orchids

Southern Marsh Orchids

Sunday 13 October 2013

It was life Jim, but not as we know it!

A different sort of natural history, but this is a photo of an Icthyosaur tooth that I found back in the summer.  It was poking out of a chunk of Jurassic limestone (Blue Lias formation) on Rhoose Point which gives it a hard to comprehend age of between 195 and 200 million years.

At that point in time the rock in which is embedded would have been somewhat nearer the equator under a warm tropical sea.  Europe and North America were joined forming the continent of Laurasia.  The earliest mammals were evolving on land.

The detail visible on the tooth is quite remarkable, it is possible to see different patterns of wear on the striations on opposite sides of the tooth, and internally the enamel is clearly differentiated from the core of the tooth, together with what looks like a perfectly circular nerve canal.

2 comments:

  1. Who's a lucky so-and-so then! I'm as green as this site's background. Geological time and the changes that occur over it are truly mind boggling, aren't they. As for detail, it is amazing the amount of fine detail that sometimes gets preserved, lending the fossil extra scientific value.

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  2. It does help to put things into perspective Mark! Also a reminder that we are potentially living in the middle of the sixth period of mass global extinctions - the Icthyosaur would have been broadly around in the Triassic/Jurassic mass extinctions. Interesting too is the value that we put on things like this. You can buy an Icthyosaur tooth forn less than a fiver, and I bought an Egyptian faience amulet (the first ceramic) which dates back to approx 2,300BC for £40 - less than the price of a meal out!

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