May 09, 2022

This morning I resurfaced an article from two weeks ago about the possible extinction of over one-fifth of the reptile species in the world.  The study examined 10,196 reptile species including turtles, crocodilians, lizards, snakes, and the tuatara (pig nosed turtle), the only surviving species of a line dating back more than 200 million years.  Researchers found 21% of species are either critically endangered, endangered, or vulnerable to extinction as defined by the International Union for Conservation of Nature (IUCN).  The study also identified 31 species that are already extinct.  Previous IUCN status reports found about 41% of amphibian species, 25% of mammal species, and 14% of bird species are threatened with extinction.  Reptiles face the same threats as other species, namely agricultural deforestation, logging and development, urban encroachment, and hunting by people.  Climate change and invasive species exacerbate the risk.

When I looked online, I found reptiles (class Reptilia) are a paraphyletic grouping comprising all sauropsid (lizard-faced) amniotes except Aves (birds), who are considered a separate class.  The earliest proto reptiles originated around 312 million years ago during the Carboniferous period and increasingly adapted to life on dry land.  In addition to the living reptiles, there are many diverse groups that are now extinct, in some cases due to mass extinction events.  Modern non-bird reptiles inhabit all the continents except Antarctica.  Reptiles either have four limbs or are descended from four-limbed ancestors (like snakes).  Most reptiles lay eggs, but several species are viviparous, meaning the fetus develops in the mother but in a non-mammalian placenta rather than being contained in a shell.  The key difference between reptiles and amphibians is their association with water for reproduction.  Reptile eggs are surrounded by membranes for both protection and transport, which adapt them to reproduction on dry land.  

I always found dinosaurs to be one of the most fascinating of reptiles.  Cultural depictions of dinosaurs have occurred since the word was coined in 1842 and range from realistic to the fantastic (monster movies).  There has been a Dinosaur Renaissance since the mid-twentieth century as science radically changed depictions of dinosaurs.  Cultural depictions have been used to reinforced misconceptions about dinosaurs and other prehistoric animals as a “prehistoric world” that portrays different periods of extinct animals (from the Dimetrodon to mammoths to cavemen) living together.  Other misconceptions that were once scientific consensus have also been overturned, such as dinosaurs being slow and unintelligent. 

THOUGHTS:  I grew up as the age of dinosaurs exploded in the last half of the 20th century.  I collected nearly 40 different types of plastic dinosaurs and could recite the length, weight, and period when each of them lived.  Other cultures have been fascinated with reptiles and have woven them into their creation stories.  My favorite is the World Turtle who carries the earth on its back or supports the heavens and is portrayed in several cultures.  When we take the time to research both living and extinct forms of reptiles, we find how fascinating and diverse they are, and we see the intricate role of reptiles is in our lives and the environment.  Both would be less without a fifth of these living species.  Act for all.  Change is coming and it starts with you.

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