The Relationship Between Dinosaurs and Birds By: Harry Layne 3/23/12 Mr. Goldfarb s Class

The Relationship Between Dinosaurs and Birds By: Harry Layne 3/23/12 Mr. Goldfarb s Class

Introduction Everybody rode their hovercrafts to the workshop on April 17 th, 2037, and sat in the showroom. The curtains on stage got pulled back, and the inventor walked out, pushing an odd machine. He said into the microphone I would like to name this machine the Holographic Three Dimensional Pre-Historic Habitat Study Projector or the H3DPHHSP for short. Everyone laughed. Archaeologists, such as Me, Myself, and I, the inventor said as the crowd laughed again. Will be able to study the behavior of ancient birds and their ancestors. Using this machine, we will discover the mysterious secrets of the bird dinosaur relationship once and for all! The crowd cheered, and the inventor turned the machine on, and the room went 65 million years into the past. People from the Press were typing franticly on portable supercomputers and taking videos on UVTDHQ cameras. Many people are itching to learn the truth Pangaea is what archaeologists called the world in the dinosaur age about this mysterious relationship. Dinosaurs and Birds are really quite similar. Back to the Prehistoric Times Relationships How did this Birds and dinosaurs may seem completely different, but they are actually quite similar. They have more than 100 features in common! They both have clawed feet, hollow bones, possibly feathers, a synsacrum, a pygostyle, 3 to 5 claws, a breastbone, and a wishbone. There are 2 different types of dinosaur hips. Saurischian and Ornithiscian. become this?

Theropods Theropods are small, carnivorous dinosaurs that may have had feathers. Some dinosaurs that make up this group are the T-Rex and Velociraptor. The Archaeopteryx, as well as any other bird, is very closely related to this dinosaur group, the Compsagnathus to be exact. In a way, you could consider birds flying Theropods. That s how closely they re related. There is a dinosaur group called Ornithomimidae, which means bird mimic. This is what an Allosaurus may have looked like. Is it a Theropod? This is what a styracosaurus may have looked like. Is it a Theropod? The Pre-Historic Environment The earliest vertebrates lived in water. They later evolved legs and began their journey to land 370 million years ago. They lived just like amphibians. The world back then was very different from the world today. Forests were filled with Cycads, Conifers, Giant Ferns, and strange plants called Williamsonias, leaving little space for the few mammals that lived there. The forests were also filled by dinosaurs (possibly feathered), lizards, birds (such as Archaeopteryx), reptiles, and Jeholodens. Jeholodens are small mammals, about the size of a rat. All these creatures lived in the Mezoic Era, with the dinosaurs, pterosaurs, and early birds. The Earliest Birds Archaeopteryx This is what the Archaeopteryx may have looked like in full color Being exceptionally large, it is 9 feet long and 2 feet high. Its wings are much like dinosaur arms, and it had long legs for running, because it couldn t fly because of its primitive wings. It could only take short glides. Its wings were clawed. Although it This is what an Archaeopteryx fossil looks like

had feathers, it had a reptilian tail, and its beak is full of teeth, unlike modern birds. It lived in the. Some say it s a bird, some say it s a dinosaur, making it all the more obvious that the Archaeopteryx is one of the most important archaeological discoveries of all time. The first fossil of the Archaeopteryx was found in 1861, and by studying its joints and bones, archeologists can tell that it either lived in trees or on the ground. The Archaeopteryx was probably a scavenger, meaning it didn t kill for food. It merely searched the land for dead meat or other things that were edible. The Archaeopteryx was also the first bird, though later came another. It was called the Rahonavis. Rahonavis This is what the Rahonavis may have looked like The Rahonavis was an ancient bird that held much evidence about this mysterious relationship. The Rahonavis had a sickle claw, much like some dinosaurs, such as the Velociraptor. The Rahonavis was discovered by Cathy Forster and Dave Krause in a quarry in Madagascar. Just like the Archaeopteryx, the Rahonavis was a primitive bird. Pterosaurs This is what a Rahonavis fossil looks like General Information Dinosaurs roamed the land. Giant Sea Reptiles claimed the sea. Pterosaurs ruled the skies. The Pterosaurs came to be at about the same time as the dinosaurs, and died out with them too. The Pterosaurs were discovered by Mary Anning, a famous archeologist. The Pterosaurs were skilled aviators. Archeologists think that to begin flight, they either got a running start, they launched out of trees, or they just began flying, much like a butterfly. This it what a Pterosaur may have looked like. This is what a Pterosaur fossil looks like.

Instead of wings, Pterosaurs use thin membranes to fly. Pterosaurs also have a wrist that can rotate in several angles Pterosaurs have an extremely long 4 th finger in which they use to hold the membrane in place. When the Pterosaurs flex their chest, the chest muscles pull the fore limbs up and down in a flapping motion. Pterosaurs also have tiny horn-like fibers scattered all over the wing membranes. These let the Pterosaurs flex the membrane in just a way that they make an umbrella shape so there s a greater air pressure underneath the membrane than above. This let the Pterosaur soar. Also, if they soar in a circle on Pterosaurs have a structure much like a bat The Draco Lizard was also a flying reptile. It uses the flaps of skin on its sides to glide. You can tell it s a boy, because it has bright yellow skin under their chins. Girls have a blue-gray color under their chin hot air or a rising air current, it lets them rise without flapping their wings or tiring them as much. This lets them fly longer. Larger Pterosaurs benefit from this technique. Pterosaurs had hollow bones. This made them much lighter for much easier flight. Some Pterosaurs may have hung upside down, much like a bat, though some Pterosaurs may have found this physically impossible, such as the long-tailed species. Their tails would have gotten in the way. But, the shorttailed species could benefit from this ability. For example, they could have enveloped themselves with their wings for warmth, or for other reasons. Different types of Pterosaurs eat either fish or insects. Pterosaurs that ate fish probably began to fly quickly, then drop near the water and skim the surface of the water. Some may have even used their tail as a rudder. Fish eating Pterosaurs also have rows of long, slender, sharp teeth on both jaws. Some archaeologists even find perfectly preserved stomach contents. Pterosaurs that caught insects had short, blunt teeth to mash up food. They caught their bugs as an in-flight snack. They also had small heads and wide mouths. Pterosaurs could fly, but they weren t birds. They were reptiles.

Groups of Pterosaurs may have formed Hatching Colonies, as they might be called. In a hatching colony, 1 or 2 adult Pterosaurs would stay and guard all the babies and Pterosaur eggs, while the other Pterosaurs hunted for food, sometimes bringing it back half digested so it could be easily eaten. This shows that Pterosaurs were probably very intelligent parents. Pterosaurs had many options to make nests. They may have scraped together earth with their long-clawed feet or they may have fashioned fallen foliage into a hollow shape. Pterosaurs, like most birds, try to keep their eggs warm. Pterosaurs either sat on their eggs or placed them in a sunbeam for warmth. Pterosaurs are coldblooded, so they warm up more easily. Once that egg hatches, one parent hunts for the whole family while the other stays to guard the baby. Pterosaurs even have a feeding pouch in their lower jaw. This lets the Pterosaur catch the food then easily bring it back to the nest. Pterosaurs were the largest creatures ever to fly, and acted much like an eagle or vulture. Their size can range from that of a sparrow to the size of a small fighter jet. There are more than 100 known species of Pterosaurs. They have 3 clawed fingers on the edge of their wings. Because there are so many different species of Pterosaurs, archaeologists broke down Pterosaurs into 2 groups: Basal Pterosauria, and Pterodactyloids. Basal Pterosauria The Basal Pterosauria used to be called Rhamphorhynchoids, but were later named Basal Pterosauria, stating they were the original type. They lived between 225 million years ago and 125 million years ago. Basal Pterosauria had long heads and short necks. Their tails were shaped much like sails, and were probably used as a rudder for flight stabability. Their size ranged from that of a robin to that of large seagull. They had large narrow wings and slender tails. There are about 2 dozen known species of Basal Pterosauria. Their fossils have been found in Italy, Germany, England India, Kazakhstan, Tanzania, Mexico, the United States, and even Antarctica. Pterodactyloids Basal Pterosauria and Pterodactyloids co-existed for 30 million years, until Basal Pterosauria died out completely. Then later, the Pterodactyloids died out 65 million years ago, with the dinosaurs. Pterodactyloids were named after the Pterodactylus, the first of its kind. Pterodactyloids appeared 150 million years ago. They are the decedents of the Basal Pterosauria.

Pterodactyloids could be considered new and improved versions of the Basal Pterosauria. For example, they were probably better at flight maneuvering than their ancestors, and their heads were longer and narrower. They have extremely short tails, and their hand bones were larger. They don t have a 5 th toe. The Pterodactyloids were a diverse group with a wide variety of sizes. Big Pterodactyloids soar, while smaller species were adept to flying fast and stealthily, and quickly changing direction. Quetzalcoatlus The Quetzalcoatlus was approximately the size of a small fighter jet, and probably had a hard time steering, caused by it lack of a tail. Its wingspan was 39 feet, and it weighed about 190 lbs! The Quetzalcoatlus was discovered in1971 in Big Bend National Park by Douglas Lawson. The Quetzalcoatlus had a very rigid neck, and it had a hard time moving its jaws, and they were toothless. The Quetzalcoatlus had a huge, elongated crest. The Quetzalcoatlus was named after Quetzalcoatl, the feathered serpent god of the Aztecs. Conclusion As the machine projected a feathered dinosaur, a Compsagnathus, the machine locked into a zoom projection and sped up. Suddenly, the room went black. I am very sorry, all of you who gathered here today. It seems the H3DPHHSP has a bug. This mystery may not be solved today, but it shall be solved in the future! The crowd let out a mix of groans and cheers, happy that they at least got to see the holographic dinosaurs. This information makes me think that dinosaurs and birds are probably related, but we don t have proof. This tells me that, because we have no proof, the relationship between dinosaurs and birds remains a mystery remains a mystery for scientists to solve.

Glossary Amphibians-Animals that live on land part of their life and in the water part of their life Ancestors-Relatives that came before you Archaeological-Having to do with archaeology Archaeologists-People who study archaeology Benefit-Thrives because of something Elongated-Extra long Evolved-Transformed into Foliage-Trees, bushes, etc. Maneuvering-Moving quickly through many obstacles Membrane-A thin layer Ornithiscian-Bird-hipped Preserved-Kept safely Primitive-First kind Pygostyle-The few bottom vertebrae Saurischian-Lizard-hipped Several-Many Stabability-Balance Synsacrum-A skeletal structure Technique-Strategy Vertebrates-Animals with vertebrae

Works Cited Arnold, Caroline. Pterosaurs Rulers of the Skies in the Dinosaur Age. New York: Clarion Books, 2004 Holmes, Thom and Holmes, Laurie. Feathered Dinosaurs The Origin of Birds. Berkeley Heights, New Jersey: Enslow Publishers, 2002 Rupert, Oliver. Archaeopteryx. Vero Beach, Florida: Rourke Enterprises Inc, 1984 Stevens, Gareth. True Life Monsters of the Prehistoric Skies. Milwaukee, Wisconsin: Gareth Stevens Publishing, 1999 Bishop, Nic. Digging for Bird Dinosaurs An Expedition to Madagascar. Boston, Massachusetts: Houghton Mifflin Company, 2000 The Franklin Institute. Giant Mysterious Dinosaurs Exhibit and Flying Monsters IMAX. Philadelphia PA Pictures Work Cited Bird Pictures http://animals.nationalgeographic.com/animals/birding/bird-photos/ And http://animals.nationalgeographic.com/animals/birds/ Draco Lizard http://animals.nationalgeographic.com/animals/reptiles/draco-lizard/?source=ato-z#