Name GEOL 104 Dinosaurs A Natural History Smithsonian Assignment I Osteology Life on Land before the Dinosaurs and the Dinosaurs Themselves DUE October 25 Every man is a valuable member of society who by his observations researches and experiments procures knowledge for men James Smithson 1765 1829 a British natural historian whose legacy of over 500 000 was given to the government of the United States of America for the creation of an Establishment for the increase and diffusion of knowledge the Smithsonian Institution The Smithsonian Institution s National Museum of Natural History NMNH has one of the largest collections of dinosaur and other fossils in the world The Smithsonian museums are free hours for the NMNH are 10 am to 5 30 pm 7 days a week You can take the Metro from the College Park Station to any of a number of stations near the Museum The quickest route is the Green Line from the UMd College Park Station to Archives Navy Memorial Penn Quarter you don t have to change trains and the NMNH is just on the other side of the Archives Building For this exercise you may wish to bring along the anatomy sheets handed out in class You may work in teams and discuss your answers however ALL WORK YOU TURN IN MUST BE YOUR OWN I have caught and reported a number of students in the past you have cheated by copying each other s work please don t make me do that again To comply with University Senate regulations please sign the following so that you may receive credit for this assignment I pledge on my honor that I have not given or received any unauthorized assistance on this assignment Signature UID NOTE Use your OWN OBSERVATIONS in order to answer the questions Throughout when given a set of choices in brackets circle the single best possible answer 1 Date Name This package works as sort of a self guided tour It will start in the Osteology Hall of Bones exhibit on the 2nd floor then move to the 1st Floor Conquest of the Land exhibit and wind up in the Dinosaur Hall PART I OSTEOLOGY For this exercise you will probably find the anatomy sheets handed out in class also available on the website a useful guide in identifying the homologous bones in these different animals In order to better understand the dinosaurs we first have to understand the anatomy behavior and ecology of modern vertebrates The Smithsonian s Osteology Bones Hall gives us an excellent opportunity for comparison We do know a lot more about modern animals their complete anatomy including soft tissue their behavior their physiology etc than we do about extinct creatures so that way we can better tell when a particular skeletal structure matches a particular behavior or function We can then take this information and apply it to extinct creatures like the dinosaurs of the Mesozoic Go to the second floor of the museum and enter into the hall labeled Bones Reptiles Insect Zoo This is one of the older halls but it contains a lot of useful specimens and information The end of the osteology exhibit proper is a chamber with the skeletons of various fish if you get to the exhibit with stuffed reptiles the Orkin Insect Zoo or the excellent temporary exhibit on forensic anthropology you ve gone to far Find the case labeled Perciform Fish and identify the swordfish Xiphias gladius It is easy to identify because it is the biggest one in the room Compare the front pectroral fin to the images below Note that only the BONES are shown the rest of the fin in both conditions is made up of thin rays 1 The bony support of the front pectoral fin of Xiphias is organized as in a b 2 Name Turn around and look on the right hand wall exhibits Find for the case labeled Flying Fish Find the skeleton of the flying fish Danichthys 2 The wings of the flying fish are actually pectoral fins Compared to Xiphias the fins are of totally different parts and structures the same underlying skeleton but of different relative proportions 3 The condition in Xiphias represents the ancestral state for this major group of fish that of Danichthys is the specialized one Thus the transformation of the fin for swimming into a wing for flying would be considered an example of which evolutionary pattern convergence exaptation heterochrony mass extinction The next hall combines the skeletons of the reptiles and amphibians We ll ignore the amphibians for this project and go to the lizards The lizard exhibit is to your left as you pass through the passage it is the other side of the wall that had Danichthys on it As you recall the first dinosaurs to be named Megalosaurus and Iguanodon were thought to be immense monitor lizards and iguanas respectively Representatives of both groups can be found in this hall Check out the skeletons of the monitor lizard Varanus bengalensis and the rhinoceros iguana Cyclura cornuata Now find the specimen of the black tegu Tupainambis negropunctatus 4 How many digits fingers per manus hand does it have 5 How many digits per pes foot does it have 6 How many sacral vertebrae hip vertebrae which connect to the ilia are present When Owen named the Dinosauria he said one of the distinguishing features of this group was their parasagittal upright stance that is their limbs were oriented directly underneath the body Look at the black tegu again 7 The limbs of the black tegu are parasagittal sprawling out to the sides 3 Name Find the skeletons of Varanus bengalensis and its relative the Gila monster Heloderma suspectum Note that these two lizards are about the same length from their shoulders to their hips 8 Based on the relative limb length Varanus Heloderma is likely the faster runner 9 What is your anatomical basis for your answer to 8 Turn left to find the crocodilian skeletons Shown are the American alligator Alligator mississippiensis the gavial Gavialis gangeticus and the black caiman Melanosuchus niger Compare the skulls of Alligator and Gavialis 10 Which genus do you think is a specialist in eating smaller fish Alligator Gavialis 11 What is your anatomical basis for your answer to 10 12 Which genus do you think was capable of eating larger fish turtles and land mammals Alligator Gavialis 13 What is your anatomical basis for your answer to 12 14 Look at the skeleton of Alligator How many sacral vertebrae hip vertebrae which connect to the ilia are present 15 The Melanosuchus specimen shows well preserved osteoderms bones in the skin Looking at the pattern of osteoderms what function do you think the osteoderms would serve for a crocodilian