Crocodiles Have Not Changed For 200 Million Years

Are Crocodiles Flawless? The Reptiles Haven’t Changed in 200 Million Years

by Elizabeth Gamillo/Smithsonianmag.com

Crocodiles are large reptiles with scaly complexions and menacing marble-like eyes. If we were to go back in time 200 million years, we would find that the crocodile’s appearance would be unchanged. Today, there are only 25 different crocodile species, a stark difference in diversity compared to birds, which appeared on the fossil record millions of years after crocodiles did but have since evolved into 10,000 other species.

In a study published this month in Communications Biology, researchers of the University of Bristol found crocodiles have kept their distinct features over millions of years and lack diversity because of punctuated equilibrium, or long periods where species are stable. During these eras, the need to evolve only arises when the animal’s environment forces them to adapt to new conditions, writes Max T. Stockdale, an expert in vertebrae macroevolution and paleontology and who was involved in the study, in the Conversation.

Fossil remains of crocodiles from as early as the Jurassic period show identifying characteristics in modern crocodiles. They both have lengthy snouts, husky tails, and rough, scaly hides. Stockdale and his team used an evolutionary mathematical model to analyze….Read More:

Carol Duff, MSN, BA, RN

Carol graduated from Riverside White Cross School of Nursing in Columbus, Ohio and received her diploma as a registered nurse. She attended Bowling Green State University where she received a Bachelor of Arts Degree in History and Literature. She attended the University of Toledo, College of Nursing, and received a Master’s of Nursing Science Degree as an Educator.

She has traveled extensively, is a photographer, and writes on medical issues. Carol has three children RJ, Katherine, and Stephen – one daughter-in-law; Katie – two granddaughters; Isabella Marianna and Zoe Olivia – and one grandson, Alexander Paul. She also shares her life with her husband Gordon Duff, many cats, and two rescues.

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