Re: Do all mammals have epiglottis? What about all creatures?

Do all animals have an epiglottis?

First, I want to make sure that we agree on what we mean by the epiglottis. The epiglottis is a special flap of cartilage (rubbery bone-like stuff) that sits in the back of the throat. It’s main job is to act as the doorway between the voice box/air tube (larynx and trachea or glottis) and the food tube (esophagus). Unless something unusual is going on, you cannot easily see the epiglottis when you look down someone’s mouth. Look at these two pictures (from Grant’s Atlas of Anatomy 10^th edition). You cannot see the epiglottis in the open mouth picture, but you can see it in the picture of the head and throat that is cut in half (sagittal cross section)

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In general, only mammals (animals like humans, dogs, cats, mice and cows) have an epiglottis. Some reptiles have an extra flap of skin that does pretty much the same thing as the epiglottis, but it does not have cartilage in it. This is an example of what scientists call an analogous structure (same job, but made in a different way) instead of a homologous structure (made in the same way – although sometimes it has a different job). Looking for analogous and homologous structures is one of the most important ways scientists workout evolutionary relationships.