Seagull
by Josie B.
The seagull is a type of bird, but birds are also very closely related to dinosaurs. The seagull has wings, feathers, and a beak that is usually yellow or orange. Seagulls usually live on beaches, but if not they live in places that are near water. Two interesting facts about my animal are they have a bone in their wings that can allow flight to happen. In addition, they are the closest relative to dinosaurs that are still alive today. But other than that seagulls are just regular birds, about the size of a small cat, can fly, and are very pesky animals.
Seagulls evolved keeled sternums, which is a bone in their wings that allow flight to happen more easily. This trait is the most advanced, so it probably separates a lot of birds or seagulls from other animals or dinosaurs. So then the seagull was able to branch off into its own group either making seagulls their own group or having a group of animals with just keeled sternums.
First seagulls evolved to be a Vertebrate, which are animals with a vertebral column and braincase. Then they evolved to be Gnathostomes, which means it has a Jaw, then it became a Tetrapod, which means it developed four Limbs. After it became a Sauropsid which means it has a pair of openings in the palate, then it evolved to be a Dinosaur which means the seagull developed a hole in the hip socket. After that the seagull became a Saurischian which means grasping hand. After it became a Theropod meaning it now only has three toes on each foot, and last it became a Maniraptor which means it developed a pulley-shaped wrist bone, ending the evolution of the Seagull.
The animal that is most closely related to the seagull on our cladogram is the Archaeopteryx. I used the cladogram to figure out what is the most closely related animal by looking at the cladogram, trace the animal branch back to the most recent node, then from that node, trace down the branch to the closest animal(s). The most advanced trait they share is the pulley-shaped wrist bone. I used the cladogram to figure this out the same way I did above. The biggest difference between these two is that the Archaeopteryx probably could fly, but not far, but the seagull can fly very far and very swiftly.
Last updated April 7, 2007.