In discovering a new dwarf sauropod, the Wilson Mantilla Lab used clues in the skeleton itself to determine whether it belonged to a young, growing individual of a large species or an adult of a small species. 

Certain bones, such as vertebrae, develop from separate components as an individual undergoes growth. Therefore, the fusion of vertebrae can offer a general indication of maturity. In the Jordan sauropod, all vertebrae are fully fused, suggesting adulthood.

Bone histology—the study of tissue-level anatomy—is a more precise method that can determine years of growth. In this case, investigation of bone histology of the Jordan sauropod—down to details of the bone cells—indicate that it is fully mature, despite its small size .... a member of an evolutionarily dwarfed species!

Meet Jeff Wilson Mantilla

Jeff Wilson Mantilla, PhD, is Professor of Earth and Environmental Science, and Curator in the Museum of Paleontology at University of Michigan. 

2008 Jordan field photos by Monica Rickhoff Wilson.

The Jordan Titanosaur

Dr. Wilson Mantilla conducts field work in India, Africa and the Middle East. Working with UM researcher Iyad Zalmout in Jordan, they have discovered the first known dinosaur of that region.

2008 Jordan field photos by Monica Rickhoff Wilson.

A new species?

Scientists go through a rigorous process of painstaking description and publication before they announce a new species’ name to the world. 

Dr. Wilson Mantilla’s evolutionary dwarf sauropod will be the first dinosaur to be named from the Arabian Peninsula. Until his findings are published, we won’t know the new species name of this Jordan titanosaur.

The bones

Dr. Wilson Mantilla shows us the various parts of the dwarf titanosaur discovered in Jordan.

Pneumatization

Sauropods are characterized by pneumatic bones, or bones with air-filled pockets. This allows for their large body size. 

Although a dwarf species, the Jordan titanosaur bones also have a high level of pneumaticity, evidence that this individual is a sauropod.

Juvenile or adult?

Dr. Wilson Mantilla wanted to determine if the fossil was a juvenile individual or a small sized adult, possibly of a new species. He looked for telltale clues on the surface of bones, and also at microscopic tissue structures inside the bones, using a process called histology.

 

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