Down to Earth Extra August 2026

The august 2026 edition of Down to Earth Extra has been published. You can down load it HERE or you can read it below.

 Ichthyotitan severnensis - Finding a New Species

I came across this WEB PAGE and from it was directed to THIS ACADEMIC PAPER. The contrast between the styles is extreme but the basis for both is the same. This is the finding of bones from the jawbone of an ichthyosaur and using the finds to describe a huge creature and erect a new species.

The bones were found by a young girl and her father on Blue Anchor Bay in Somerset and the creature is estimated to be 25m long. It was realised that a similar jawbone had been found some time earlier in the same rock layer, at a nearby locale. This was sufficient for a new species to be postulated.

A washed-up Ichthyotitan severnensis carcass on the beach. Credit: Sergey Krasovskiy.

The story of the find shows that amateur geologists can still be important in our science. And it is cheering to note that they both appear among the authors of the academic paper.

The paper has a long description of the find and a discussion about the naming of a new species. And it asks that if you find something similar to contact them! And they would be delighted if you could find a complete specimen of the animal!

 Did Complex Life Appear Because the Magnetic Field was Weak?

Some parts of the history of the Earth's magnetic field are easy to measure. But the strength of the field is not one of them. We have lots of information of the reversals of the polarity of the field and the direction of the magnetism - think of the stripes on the ocean floor and knowing the latitude of when rocks were laid down - but the field strength of the field is harder to come by.

And this is important for the presence of the field is what protects us from deadly cosmic rays. It is very possible that no field = no life.

But some measurements of field strength have been made and one of the interesting things is that it was very low in the Ediacaran. It was a fifteenth of the present value. This and the consequences of this are discussed in THIS ARTICLE.

Did the reduction in magnetic field strength allow more genetic mutation in the single-celled creatures promoting the multi-celled Ediacaran fauna?

The article goes on to discuss the mechanism which affected the field, essentially the formation of the Earth's inner core. The 100 million years this took covers the Ediacaran and the "Cambrian Explosion".

The article gives a pleasing combination of Earth physics and biology. It may even be true!