Holotypes and Species Identification in Paleontology

6 Questions

What is the role of Joyce Havstad at The Field Museum?

Philosopher in Residence

What are holotypes?

Representatives and exemplars of a species

Why are holotypes important in identifying new species, especially in the case of the fossil record?

To serve as representatives and exemplars of a species

What did Elmer Riggs recognize about the Brachiosaurus holotype?

Its femur to humerus ratio was longer in the humerus

What insight does the ratio between the femur and humerus provide about Brachiosaurus?

It suggests their likelihood of feeding on foliage from trees

What is the concept of holotypes analogous to, according to the text?

The idea of a universal standard of measurement like the meter

Study Notes

Joyce Havstad, known as the Philosopher in Residence at The Field Museum, discusses her role and her research on holotypes.
Holotypes are the physical specimens that serve as the representatives and exemplars of a species.
The concept of holotypes is important in identifying new species, especially in the case of the fossil record where complete skeletons may not be available.
The idea of a universal standard of measurement, like the meter, can be compared to the concept of holotypes in identifying species.
Brachiosaurus is a well-known example of a dinosaur with an incomplete skeleton, with only about 20% of the whole skeleton discovered.
Elmer Riggs, a Field Museum scientist, discovered the Brachiosaurus holotype in 1900 and recognized its uniqueness due to the ratio of the femur to the humerus being longer in the humerus, making it appear to have a tilted back and long neck.
Other closely related sauropods have been named after the giraffe due to their similarities in having shorter legs and longer arms, tilting them up like a giraffe.
The ratio between the femur and humerus provides insight into the ecology of the species, suggesting that Brachiosaurus likely fed on foliage from trees rather than grazing on grass.
Paleontologists use careful analysis and critical thinking to determine whether partial skeletons represent new species, based on characteristic features and comparisons to known holotypes.
Discovering a new species and identifying it as a holotype is an exciting process for scientists, providing new knowledge and insights into the natural world.