After only swimming the oceans for the blink of an eye, the fate of a poor baby ichthyosaur was sealed. But that was enough time for it to reveal to researchers hundreds of millions of years later the behavior of the youngest of these creatures.
Scientists have described what they believe is the youngest and smallest specimen of Ichthyosaurus communis ever discovered. The tiny fossil only measures 70 centimeters (2.3 feet) in length, but the exquisite detail of the preservation means that the tiny fossil has revealed some incredible insights into the animal, including its last meal before death.
“It is amazing to think we know what a creature that is nearly 200 million years old ate for its last meal,” says Dean Lomax, who led the research published in Historical Biology, in a statement. “We found many tiny hook-like structures preserved between the ribs. These are from the arms of prehistoric squid. So, we know this animal's last meal before it died was squid.”
This is interesting because it helps to piece together what the ecosystem may once have looked like at the time. While this little fossil is the youngest Ichthyosaurus ever discovered, there have been other babies from different species of ichthyosaurs found, and their stomachs revealed something else entirely.
One such example is that of ichthyosaurs known as Stenopterygius. This species lived later than the subject of this new study, but research has shown that the young of Stemopterygius fed predominately on fish, leading scientists to believe that perhaps newborn ichthyosaurs focused on prey covered in scales, before moving on to squid as they matured. It now seems that instead of this, the young of different species had different feeding strategies from the start.
However, as is often the case when researchers discover a long-hidden gem in the back room of a museum, there are many missing details about the fossil, such as its age. While the vast majority of all fossils belonging to the Ichthyosaurus genus have been found exclusively in the UK, the exact location of where this specimen was originally collected was not recorded.
Yet, the researchers were able to glean some additional information from the slab of rock the bones were still preserved in. The microfossils lying alongside the baby ichthyosaur can be used to date the fossil, and they point to it being around 199 million years old. This provides valuable details as to the age, although as rocks of this period are fairly common across the UK, it doesn’t help to narrow down where it was first collected.