The Iguanodon's Thumb
About six months after my drawing of Iguanodon through the ages, I did another piece taking a closer look at the dinosaur as we now see it, in part because the modern reconstruction was easily the hardest the capture on paper.
This drawing is strictly of Iguanodon bernissartensis, currently recognized as the only valid species (though ironically, the original Iguanodon bones have now been ascribed to a new genus called Mantellisaurus, in honor of the animal's initial describer Gideon Mantell). Here's a closer look:
The specimen sketched is from the Senckenberg Museum in Frankfurt, Germany.
The term "Swiss Army hand" was coined by paleontology Thomas R. Holtz in the wonderful Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages (Random House, 2007). Even with its impossible-to-live-up-to title, it's a must-own for anyone vaguely curious about dinosaurs.
Growing up, the explanation for Iguanodon's thumb spike was that it was a weapon against predators. As Holtz and other paleontologists have pointed out, this premise makes little sense, since surely an Iguanodon who got close enough to jab at a large theropod with its thumb would also be close enough for this attacker to take a large bite out of the herbivore. Since the animal is now thought to have been mostly quadrupedal, the big claws of the middle three fingers now seem to have been for bearing its weight as it walked, while the dangling pinkie may have been for grasping the branches it fed from. But now that defense has been discarded, the question how Iguanodon used its claw is wide open.
About six months after my drawing of Iguanodon through the ages, I did another piece taking a closer look at the dinosaur as we now see it, in part because the modern reconstruction was easily the hardest the capture on paper.
The specimen sketched is from the Senckenberg Museum in Frankfurt, Germany.
The term "Swiss Army hand" was coined by paleontology Thomas R. Holtz in the wonderful Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages (Random House, 2007). Even with its impossible-to-live-up-to title, it's a must-own for anyone vaguely curious about dinosaurs.
Growing up, the explanation for Iguanodon's thumb spike was that it was a weapon against predators. As Holtz and other paleontologists have pointed out, this premise makes little sense, since surely an Iguanodon who got close enough to jab at a large theropod with its thumb would also be close enough for this attacker to take a large bite out of the herbivore. Since the animal is now thought to have been mostly quadrupedal, the big claws of the middle three fingers now seem to have been for bearing its weight as it walked, while the dangling pinkie may have been for grasping the branches it fed from. But now that defense has been discarded, the question how Iguanodon used its claw is wide open.
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