Table 1: The times of first appearance (FAD) and last appearance (LAD) for some groups of dinosaurs. Use
this chart to answer the questions below.
Group
Earliest Geologic Period
Earliest Geologic Age
FAD (Ma)
Latest Geologic Period
Latest Geologic Age
LAD (Ma)
Stegosauria
Jurassic
Callovian
166
Cretaceous
Coniacian
86
Ornithopoda
Jurassic
Sinemurian
199
Cretaceous
Maastrichtian
66
Ankylosauria
Jurassic
Callovian
166
Cretaceous
Maastrichtian
66
Ceratopsia Jurassic
Tithonian
152
Cretaceous
Maastrichtian
66
Pachycephalosauria
Jurassic
Tithonian
152
Cretaceous
Maastrichtian
66
Sauropoda Triassic
Carnian
237
Cretaceous
Maastrichtian
66
Theropoda Triassic
Landianian
242
Cretaceous
Maastrichtian
66
Utahraptor
(genus)
Cretaceous
Hautervian
130
Cretaceous
Barremian
125
Tyrannosaurus
(genus)
Cretaceous
Maastrichtian
68
Cretaceous
Maastrichtian
66
Triceratops
(genus)
Cretaceous
Maastrichtian
68
Cretaceous
Maastrichtian
66
Iguanodon
(genus)
Cretaceous
Barremian
126
Cretaceous
Aptian
122
•
If you found a deposit containing specimens of BOTH Stegosauria and Ornithopoda, what is
the potential age range (maximum and minimum age in millions of years, Ma) of that deposit?
86Ma-166Ma
•
If you found a deposit containing specimens of Pachycephalosauria AND Sauropoda, what is the oldest
possible age (in millions of years) of that deposit?
152Ma
•
If you found both Utahraptor
and Iguandon
in the same deposit, what is the potential age range (maximum and minimum age, in millions of years) of that deposit?
125Ma-126Ma
•
In a popular film, Utahraptor
and Tyrannosaurus
have a scene together. Would this have been possible in the real world? Provide your evidence and explain your reasoning. This would not have been possible. The Utahraptor last appeared 57 million years before the tyrannosaurus first appeared. Therefore, they were not alive at the same time and thus could not have been alive together.
•
In an even older popular animated film, Triceratops
co-stars with a sauropod.
Would this have been possible in the real world? Provide your evidence and explain your reasoning. Yes this would have been possible. Both the triceratops and the sauropod last appeared 66 million years ago. The sauropod first appeared 237 ago and the triceratops first appeared 68 millon years ago. Therefore, they were alive at the same time and could have been seen together.
•
Why might we use genera in biostratigraphy rather than broader taxonomic groups?
I think genera are used because it allows scientists to organize data more clearly. Also, certain genera may be in the same taxonomic group when looking at one broader than the genus, but they may not have been alive at the same time. One could have started
