The ancient crocodile Pakasuchus kapilimai once roamed the Middle Cretaceous of Tanzania. No larger than a housecat, the animal had a number of features unusual for crocodylians, including mammal-like teeth.
Credit: Zina Deretsky, National Science Foundation
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A photograph of the postcranial skeleton of Pakasuchus kapilimai as it appears partially prepared out of the red sandstone matrix. The researchers used a sandbox and foam padding (in blue) to position the separate fragments of the fossil prior to photographing the specimen.
Credit: Patrick M. O'Connor, Ohio University
Image size: 4.40 MB

This line-drawing draft of Pakasuchus kapilimai was completed by Ohio University graduate student Haley O'Brien.  The drawing simplifies the complexity of the partial skeleton presented in the above photograph, delineating the position of the vertebral column, the tail (at the top, covered with osteoderms), and limb elements.
Credit: Haley O'Brien, Ohio University
Image size: 5.21 MB

Artist’s rendering of Pakasuchus kapilimai.
Credit: Mark Witton, University of Portsmouth
Image size: 2.64 MB

Using a medical scanning technology called X-ray computed tomography, the researchers were able to create detailed digital images of the Pakasuchus kapilimai teeth accurate to 45 micrometers (millionths of a meter). Because the images were digital, they were ideal for animation, enabling the researchers to observe how the teeth fit with one another and estimate how the jaw may have moved.
Credit: Ryan Ridgely and Patrick M. O'Connor, Ohio University
MOV (7.02 MB)

Left-lateral view of the skull of Pakasuchus kapilimai within its original red sandstone matrix.
Credit: John Sattler, Ohio University College of Osteopathic Medicine
Image size: 2.65 MB

A Nile crocodile smiles for the camera in Queen Elizabeth National Park, Uganda.
Credit: Nancy J. Stevens, Ohio University
Image size: 452 KB

This panorama shows one of the research team’s field vehicles on site in the Rukwa Rift Basin in Tanzania.
Credit: Patrick M. O'Connor, Ohio University
Image size: 2.64 MB

Patrick O'Connor examines the portion of exposed bone fragments that would ultimately yield the holotype specimen of Pakasuchus kapilimai. Coauthor and project student geologist Zubair Jinnah found the specimen while prospecting.
Credit: J.P. Cavigelli, Tate Museum, Wyoming
Image size: 1.94 MB

Saidi Kapilima (foreground, and for whom Pakasuchus kapilimai is named) and graduate student Sifa Ngasala (background) take a short break while hand-quarrying for fossils.
Credit: Patrick M. O'Connor, Ohio University
Image size: 684 KB

Artist’s rendition of Pakasuchus kapilimai dentition, highlighting the mammal-like motions the jaw may have produced during eating.
Credit: Zina Deretsky, National Science Foundation
Image size: 73 KB

Nile crocodile in Queen Elizabeth National Park, Uganda, illustrating modern crocodile dentition.
Credit: Nancy J. Stevens, Ohio University
Image size: 337 KB

Ohio University graduate students Erin Simons (top right) and Verne Simons (foreground right) apply plaster bandages to a small dinosaur jacket at the field site in the Rukwa Rift Basin of southwestern Tanzania.
Credit: Patrick M. O'Connor, Ohio University
Image size: 3.11 MB

Eric Roberts (left), Nancy Stevens (second from left), Verne Simons (second from right) and Tobin Hieronymus (right) hand-quarry for fossils in the Rukwa Rift Basin of southwestern Tanzania.
Credit: Patrick M. O'Connor, Ohio University
Image size: 1.19 MB

Patrick O'Connor and Sifa Ngasala excavate a dinosaur limb bone out of a cliff face on the Mtuka River, while Nancy Stevens and Erin Simons collect fossils along the edge of the riverbed.
Credit: Eric Roberts, James Cook University
Image size: 1.21 MB

Ohio University graduate students Erin Simons (left) and Verne Simons (right) work with Patrick O'Connor (center standing) on a dinosaur excavation in the Rukwa Rift Basin of southwestern Tanzania, while local village children look on at the proceedings.
Credit: Nancy J. Stevens, Ohio University
Image size: 745 KB

Eric Roberts and Patrick O'Connor (on cliff) prepare a fossil block for removal from the cliff wall, while Verne Simons and Sifa Ngasala watch below from the river bed.
Credit: Nancy J. Stevens, Ohio University
Image size: 4.00 MB

Jesuit Temba of the Tanzania Antiquities Unit prospects for fossils in the Rukwa Rift Basin of southwestern Tanzania.
Credit: Verne Simons, Ohio University
Image size: 821 KB

University of Dar es Salaam students Ahmed Mussa (left), Gabriel Masai (center) and Michigan State University student Sifa Ngasala (right) hand-quarry for fossils in the Rukwa Rift Basin of southwestern Tanzania.
Credit: Verne Simons, Ohio University
Image size: 2.46 MB