Recently, a fossil was discovered in Scotland that reveals clues about the evolution of reptiles in Europe. The fossil that was discovered is a new genus of "ichthyosaur", a reptile that ruled the seas during the Middle Jurassic period. It is around 14 feet long, and is the first of its kind to be discovered by paleontologists.
The new fossil comes from a time during the Middle Jurassic period that scientists know very little about. Scientists do know that after the Middle Jurassic period, there was a larger and more advanced type of ichthyosaur that becomes dominant around the world. The fossil found in Scotland is a smaller and more primitive type of ichthyosaur, revealing that the transition to the more advanced type of ichthyosaur happened later than scientists had thought. The discovery of this smaller fossil also indicates that the transition to the larger ichthyosaurs was a gradual shift, not a sudden shift due to a change in environment.
This connects to our study of evolution in class. This small version of ichthyosaur shows that the change to the bigger ichthyosaurs was a slow and gradual change, as the ichthyosaurs underwent natural selection and the better fit traits were passed on. The smaller ichthyosaur pinpoints a more exact rate at which the ichthyosaurs evolved.
Does this new information change how we think about evolution of other dinosaurs?
ReplyDeleteSpecifically, what changes occurred in the evolution from the smaller ichthyosaurs to the larger ones and how were they more fit?
ReplyDeleteThe new information doesn't necessarily change how we think about the evolution of the other dinosaurs; the finding of this fossil mostly just gave us a better view on when they evolved. Scientists had a pretty clear idea on how they evolved, so I don't think this changes how we think about evolution of other dinosaurs, but some new evidence could change that.
ReplyDeleteThe larger ichthyosaurs are generally bigger and more advanced. Surprisingly, paleontologists found that they have maintained the same body shape, including chests and fins, as their earlier relatives in the Jurassic period. There actually isn't much evidence because very few fossils have been found. These new ichthyosaurs are just better predators and larger, but we can still only guess at why they were more fit and how the change happened.
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