GEOL 104 Dinosaurs: A Natural History
Smithsonian Assignment II: Dinosaurs, Mesozoic Marine Life, and the Cenozoic Era (but mostly dinosaurs)
DUE: December 6
The Smithsonian Institution’s National Museum of Natural History (NMNH) has one of the largest collections of dinosaur and other fossils in the world. This exercise will concentrate on the wonderful dinosaur fossils on exhibit.
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: 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 dinosaur cladograms handed out in class. You may work in teams and discuss your answers; however ALL WORK YOU TURN IN MUST BE YOUR OWN. 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
This package works as sort of a self-guided tour. It will start you at one end of the Dinosaur Hall, then lead you through that Hall (including the upstairs), then through the Mesozoic section of the Life in the Ancient Seas Hall, and finally take you into the Hall of Fossil Mammals and Hall of Ice Age Mammals to get a glimpse at life after the Age of the Dinosaurs.
Some things to keep in mind:
When asked for number of fingers (or number of toes), answer in the number PER HAND (or Per Foot)!
Remember proper handwritten taxonomic grammar:
Genera have one-word, capitalized, and underlined names:
Examples: Giganotosaurus Brachiosaurus
Species have two-word, underlined names; the first part of the name (which is the same as the genus name) is capitalized, but the second part of the name is not:
Examples: Giganotosaurus carolinii Brachiosaurus altithorax
When given a choice of items in bracket, circle the appropriate answer.
PART I – THE DINOSAUR HALL
Enter the main Dinosaur Hall, and take the right path (the side with the model of the Stegosaurus). Follow the railing of the central “island” (the group of skeletons in the central region), passing some sauropods and Stegosaurus. Stop at the Allosaurus skeleton.
Examine the Allosaurus fragilis skeleton.
1) How many fingers (per hand) does it have?
2) How many toes (per foot) does it have?
3) Which description better matches the shape of the skull?
a. Very broad, nearly as wide or wider side to side than it is tall dorsoventrally.
b. Narrow, much thinner side to side than tall dorsoventrally.
4) Is the third metatarsal pinched proximally (i.e., does the foot have an arctometatarsus)? [ Yes | No ]
5) Examine its left scapula. In a normal individual this bone has a simple strap shape. Draw the bone as it is in this specimen.
6) What do you think might have happened to this bone?
[Note that the real ribs of this specimen (which are in the collections rather than on display) are damaged along the left side, and the left dentary was so damaged and rehealed in such an unusual way that it was thought to be from a whole new dinosaur (named “Labrosaurus”).]
Move past the skeleton of the Stegosaurus, which is being taken apart for repairs and digital scanning, and find a pair of sauropod skulls. One is the macronarian Camarasaurus, and one is the diplodocoid Diplodocus.
7) [ Camarasaurus | Diplodocus ] has a larger naris.
8) [ Camarasaurus | Diplodocus ] has larger teeth.
9) [ Camarasaurus | Diplodocus ] has pencil-shaped teeth.
Extra Credit) Both Camarasaurus and Diplodocus were [ carnivores | herbivores ].
Some of the dinosaurs in this museum are shown in “life position” (mounted as if the animal were standing or walking and suddenly all the flesh and viscera disappeared) and others are in “death position” (mounted in the position the skeletons were found in the rock).
10) The Camarasaurus lentus skeleton directly nearby the two sauropod skulls from the previous question is in
[ life | death ] position.
Almost all the dinosaurs in the central “island” are from the Morrison Formation of the American West (Wyoming, Colorado, Utah, Montana, etc.).
11) In what Epoch was the Morrison Formation deposited (in other words, in what Epoch did these dinosaurs live)?
[ Late Triassic | Early Jurassic | Middle Jurassic | Late Jurassic | Early Cretaceous | Late Cretaceous ]
Move along and examine the cast of Tyrannosaurus rex. It is mounted facing off with its contemporary, Triceratops.
12) How many fingers (per hand) does it have?
13) How many toes (per foot) does it have?
14) Is the third metatarsal pinched proximally (i.e., does the foot have an arctometatarsus)? [ Yes | No ]
Move over past the steps to the other wall of the Dinosaur Hall. The Marginocephalia exhibit is the newest exhibit in the Dinosaur Hall. Its centerpiece is a specimen of Triceratops nicknamed “Hatcher”.
15) What is the full species name of this specimen?
16) How many fingers (per hand) does it have?
17) How many toes (per pes) does it have?
18) The hindlimb of Triceratops is much longer than the forelimb. In some animals this is used as a suggestion that the creature was a biped. Do you think Triceratops could have walked in a bipedal mode? Why (or why not)?
Other than Triceratops, specimens of three genera of true ceratopsids are on display. One is down the stairs, past the video monitors; the other two are in a glass case to the right of Triceratops and some smaller marginocephalians. Indicate to which of the two ceratopsid subclades these different genera belong. Note: this exhibit uses the name “chasmosaurines” for the group we refer to in class as Ceratopsinae.
19) Diceratops (lower level): [ Centrosaurinae | Ceratopsinae ]
20) Centrosaurus (glass case): [ Centrosaurinae | Ceratopsinae ]
21) Styracosaurus (glass case): [ Centrosaurinae | Ceratopsinae ]
Extra Credit) Which of these genera is represented by a juvenile individual?
Primitive (non-ceratopsid) ceratopsians are represented by three skulls: Protoceratops, Bagaceratops, and Psittacosaurus.
22) In which of these primitive ceratopsians is the frill the longest, in terms of relative size to the rest of the skull?
Extra Credit) Several pachycephalosaurs are also on display here. What is the full species name of the largest pachycephalosaur on exhibit?
Thescelosaurus neglectus and Heterodontosaurus tucki are both mounted on the wall near the Marginocephalia exhibit.
23) These two dinosaurs are both representatives of
[ Thyreophora | Sauropodomorpha | Ornithopoda | Theropoda ].
24) [ Thescelosaurus | Heterodontosaurus ] is the larger of the two.
25) [ Thescelosaurus | Heterodontosaurus ] is the older of the two.
Move along to the hadrosaurids. The complete skulls of an adult hadrosaurine and of a juvenile lambeosaurine are on display. Which species are represented by these skulls?
Extra Credit) Which genus has the proportionately longer and wider bill?
Pass the cast of the Tyrannosaurus rex skull, and move down the line. Examine the skeleton of Ceratosaurus nasicornis. This is the type specimen (the original one to which the name was assigned). New research indicates that it wasn’t fully grown when it died.
28) How many fingers does it have?
Extra Credit) Ceratosaurus is a [ carnivore | herbivore ].
Turn around and face the main island.
29) What dinosaur species is shown in death position at this point?
(Incidentally, note the bony armor knobs around the cervical vertebrae).
Somewhat out of place on the central island (since they are not from the Morrison Formation like the others) are the eggs of Troodon and the baby Maiasaura skeleton. Maiasaura is a hadrosaurine hadrosaurid.
30) Does this hatchling specimen show the characteristic extremely large nostrils and very broadly expanded snout of the adults? [ Yes | No ]
Look at the pair of skeletons of the primitive iguanodontian Camptosaurus. Once labeled as separate species, these are now considered different growth stages of the same species (C. dispar).
31) Based on the position of the two mounts, Camptosaurus is best considered a(n):
[ obligate biped | facultative biped | obligate quadruped ].
32) What unusual feature do you see on the right ilium of the larger of the two Camptosaurus skeletons in the main island?
Examine the enormous skeleton of Diplodocus longus dominating the Hall. Rank (from the longest section to the shortest section) each of the sections of the vertebral column (cervical, dorsal, sacral, and caudal):
33) Longest: Second longest: Third longest: Shortest:
34) How many metacarpals (per hand) does Diplodocus have?
35) How many metatarsals (per foot) does Diplodocus have?
Extra Credit) Find the distalmost caudals (i.e., the tip of the tail) of Diplodocus. Circle whichever of the following is a better description of the anatomy of these bones:
Very complex, with large transverse processes and tall neural spines
Very simple, with no transverse processes and no neural spines
36) Find the enormous limb bone of Brachiosaurus altithorax on display (this is a specimen you can touch). As precisely as possible, which bone is this? (Use the sign on the display for help)
Go back around to the other side of the exhibit, and go towards the stairs to the upper deck of the Dinosaur Hall (near the pterosaurs and such). Before walking up the stairs, examine the small display of Mesozoic mammals and insects.
37) The tiny Mesozoic mammal fossils are all represented by what general part of the body?
Now head up the stairs. From the upper deck of the Dinosaur Hall, find the overlook and look down at the central island. Look at the dinosaurs from above.
38) [ Theropods | Herbivores ] tend to have the narrower hips.
39) What reason might there be for this?
Turn around and look at the pterosaur exhibit.
40) The distal part of the pterosaur wing is comprised of digit [ I | II | III | IV | V | VI | VII ].
Now compare the specimens of Pteranodon (represented by an isolated wing and a complete skeleton) with the skeleton of Campylognathoides liassicus to the right.
41) [ Pteranodon | Campylognathoides ] is a larger animal.
42) [ Pteranodon | Campylognathoides ] has a proportionately longer tail.
43) [ Pteranodon | Campylognathoides ] has a proportionately longer metacarpus.
44) [ Pteranodon | Campylognathoides ] lived earlier in time.
Walk up the ramp a bit. Find the exhibit sign labeled “What’s for Dinner?” that describes the two wall-mounted specimens on the opposite wall: the tyrannosaur Albertosaurus (actually Gorgosaurus) and the hadrosaurine Edmontosaurus).
45) Indicate which one is in life position and which one is in death position (although at 90º from the original flat surface!).
Life position: [ Albertosaurus | Edmontosaurus ]
Death Position: [ Albertosaurus | Edmontosaurus ]
The directions on the next page will direct you to the next section of this project
PART II – MESOZOIC MARINE LIFE
From the “What’s for Dinner?” plaque, head back downstairs, past the Morrison Formation island, down the small stairs between Tyrannosaurus and Triceratops, and take a right turn into the Hall of Ancient Life in the Seas. Once there, take a right (that is, go underneath the sign labeled “Act Two – The Mesozoic Era”). This hall documents vertebrate, invertebrate, and plant life throughout the last 544 million years with fossils, a great mural, and some life restoration models hanging about. The particular section you are in contains exhibits on the marine life of the Age of Dinosaurs.
Find the Mesozoic marine reptiles. These are mounted in front of or directly below the mural (and a few are in glass cases along the rail). In the list below, indicate by letter if the marine reptile is a(n):
A) bird B) turtle C) plesiosaur D) nothosaur E) placodonts F) ichthyosaur
G) marine “crocodilian” (technically a non-crocodylian crocodyliform) H) mosasaur
46) Tylosaurus proriger
47) Steneosaurus bollensis
48) Hesperornis regalis
49) Dolichorhychops osborni
50) Neusticosaurus sp.
51) Stenopterygius quadricissus
52) Macroplacus raeticus
53) Prostega gigas
54) Out of the list of species above, give an example of a marine reptile with a rather rigid body and four large flippers:
55) Out of the list of species above, give an example of a marine reptile with an elongate body with a long tail:
56) Out of the list of species above, give an example of a marine reptile with a long snout with conical teeth:
Extra Credit) Out of the list of species above, give an example of a marine reptile with large blunt crushing teeth:
The seas of the Mesozoic, like those of today, had diverse types of “shellfish” (invertebrates). Many examples are on display: some along the wall with the main mural, others in the center “island”, and still others on their own display labeled “Taking Cover” on the wall opposite from the main mural. In the list below, match the invertebrate group with the letter of the appropriate description:
57) Ammonites (in center island and in “Taking Cover”):
58) Rudists (near the Tylosaurus proriger skeleton):
59) Inoceramus (“Taking Cover”):
60) Exogyra (“Taking Cover”):
A. A type of oyster.
B. A diverse group of (primarily coiled) shelled relatives of modern octopi, squid, and Nautilus.
C. A large flat-shelled clam.
D. A group of large surface dwelling clams, some with a conical form, others with a “horseshoe” shape.
Move down the Hall of Ancient Life in the Seas into the next section (“Act Three – The Cenozoic Era”), and take a right up the steps labeled “Reptiles: Masters of the Land”. On the wall opposite those steps is a small exhibit on the Cretaceous-Tertiary impact and extinction. This exhibit includes a real deep-sea drilling core that actually contains the stratigraphic boundary from the Cretaceous Period to the Tertiary Period.
61) At what location (where in the seas) was this core taken?
PART III – LIFE AFTER THE AGE OF DINOSAURS
Now you’ll be heading to the fossil mammal halls. From the Cretaceous-Tertiary exhibit, turn left. Turn right (the only option), and then turn left again. You should be facing the entrance to the Hall of Fossil Mammals, with a sign labeled “Mammals in the Limelight”.
Extra Credit) There is a wonderful mounted skeleton of Hyracotherium vasacciensis on display. What modern animal is Hyracotherium’s closest living relative?
Pass the Hyacotherium and head over to the start of the hall (a glass case display of Mesozoic mammals). In general, as you follow the Hall of Fossil Mammals along you proceed upwards in time, tracing the history of North American mammals, other animals, and their environment through the Cenozoic Era. Each exhibit is organized by Epochs. Cenozoic Epoch names are different from those in the rest of geologic time: instead of being in the form “Late Jurassic Epoch” or “Early Permian Epoch”, each is given a unique name. From oldest to youngest, they are the Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, and Holocene (or Recent). The last two Epochs are part of the Quaternary Period, and have their own hall (the Hall of Ice Age Mammals). The rest are the Tertiary Period, and represent the exhibits in the main Hall of Fossil Mammals.
Compare the actual fossils (not the enlarged white models) of Mesozoic mammals with those of the Paleocene mammals.
62) What is the most obvious change in the mammals from the Mesozoic to the Paleocene?
The rest of the Tertiary is organized with a series of paintings in the back and the actual fossils and casts of fossils arrayed in front. Start with the Eocene exhibit.
63) Which seem to be more common in the Eocene, quadrupedal mammals or bipedal mammals?
Extra Credit) How many bipedal Eocene mammals can you find? Name them.
64) Diatryma steini is one of the larger Eocene animals on display. What sort of animal is it?
Look at the skeletons of Oligocene through Pliocene mammals in this hall.
65) Are there any Diplodocus-sized mammal skeletons in these exhibits? If so, name one.
66) Are there any Tyrannosaurus-sized mammal skeletons in these exhibits? If so, name one.
67) Are there any Stegosaurus-sized mammal skeletons in these exhibits? If so, name one.
Move into the Hall of Ice Age Mammals. As you enter, there is an exhibit of some odd mammals off to your left.
68) What species of gigantic facultative bipedal mammal (two specimens are show) is exhibited?
Extra Credit) What was its diet?
69) Mammals, like dinosaurs and pseudosuchians, developed their own form of heavily armored herbivore. What is the species of mammal shown here which is generally convergent on the tank-like ankylosaurs of the Mesozoic?
70) There are only three species of mammal in this hall which would rival (or perhaps even surpass) the mass of a Triceratops or Tyrannosaurus. One was the facultative biped in question 68. Name one of the two remaining giant Ice Age mammal species on exhibit, with extra credit for the second.
Extra Credit) What modern animals are most closely related to the giant Ice Age mammals in question 70?
While you are in the museum, use your time to examine some of the other exhibits.