In dinosaurs as in many reptiles (and some mammals such as kangaroos), a chevron (aka haemal arch) is an inverted arch or "V"-shaped bone that hangs beneath each tail vertebra.
Where chevron meets vertebra a "tunnel" is formed through which the nerves, artery and vein of the tail pass, and it's the chevron's job to protect these critical elements when the tail is exposed to pressure on the underside.
When several vertebrae and their corresponding chevrons are joined together to form the tail, the "tunnels" are collectively known as the "haemal canal".
Where chevron meets vertebra a "tunnel" is formed through which the nerves, artery and vein of the tail pass, and it's the chevron's job to protect these critical elements when the tail is exposed to pressure on the underside.
When several vertebrae and their corresponding chevrons are joined together to form the tail, the "tunnels" are collectively known as the "haemal canal".
recommended
• Thomas R. Holtz, Jr (2008) "The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages".
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