This week we’re heading back to the early Jurassic seas to meet the Ichthyosaurs, the first marine reptile ever discovered, and one of the most recognizable.
At first glance, it looks uncannily like a dolphin… but Ichthyosaurus wasn’t a mammal, and it definitely wasn’t a fish, though the name Ichthyosaur means 'Fish-Lizard'. It was a marine reptile like the Mosasaurs, returning to the sea long before whales ever did. Nature and evolution just knows a good streamlined design when it sees one.
Ichthyosaurs had huge eyes (some of the largest of any animal, living or extinct), perfect for hunting in deep or murky water. Their long jaws were packed with sharp teeth, ideal for snapping up fish and squid, and their powerful tails helped them cruise the oceans with ease.
This week’s sketch shows that classic torpedo-shaped body, fins, flippers, a shape so efficient it evolved independently in completely different groups millions of years apart.
Ichthyosaurus fossils were especially important in the early days of paleontology. In the early 1800s, collectors like Mary Anning helped bring these creatures to scientific attention, proving that entire groups of animals had lived, and then vanished, all long before humans ever existed.
Fun fact: Ichthyosaurs gave birth to live young, not eggs. Fossils have even been found mid-birth, frozen in time for nearly 200 million years. That has to be a record for time spent in labour right?!
