[1] A complete specimen of Lazarussuchus with preserved soft tissue was found from the Late Paleocene of France, but has not been assigned to a species.
[3] The first remains of Lazarussuchus, belonging to the type species L. inexpectatus were described in 1992 from a mostly complete articulated skeleton (Claude Bernard University no Re 437, coll.
Gennevaux 92813) found in the Upper Oligocene aged sediments of the Armissan limestone quarry near Narbonne in Aude, France.
[1] In 2005 another species, L. dvoraki, was described from isolated skull bones and vertebrae from the Early-Middle Miocene sediments of the Merkur-North locality in the north-west Czech Republic.
The Hammerschmiede locality has been dated magnetostratigraphically to the base of the Tortonian stage of the Late Miocene, approximately 11.62 million years ago.
[3] L. inexpectatus is distinguished by having the postparietal processes of the parietal bone equal or nearly equal in length to the parietal plate, directed posteriorly with less than 30 degrees of angulation and only weakly concave, resulting in the upper temporal fenestra being elongated and almost rectangular in shape, with an anterior-posterior long axis, nine cervical vertebrae are present, the posterior portion of the trunk vertebrae have spinous processes below the postzygapophyses that act as additional articular surfaces, four functional sacral vertebrae are present, of which the first is a sacrodorsal, and a slender T-shaped interclavicle.
L. dvoraki is distinguished by having postparietal processes only 1/3 of the length of the parietal plate, which are angulated greater than 45 degrees laterally and a concave lateral margin, resulting in the upper temporal fenestrae being smaller and more ovoid in comparison to L. inexpectatus, with a antero-medial to posterolateral long axis, and the trunk vertebrae lack articular spinal processes.
[4] The Menat specimen of Lazarussuchus preserves some remnants of soft tissue, but no scales, which shows that the hindfoot (pes) was not webbed, and a dark stained region with a crenellated edge is present above the caudal vertebrae of the tail, suggestive of a crest similar to those found in some living reptiles, like the tuatara, lizards and crocodiles.
The crocodile-like neochoristoderes went extinct at the start of the Eocene, possibly due to climatic changes happening at this time, known as the Paleocene-Eocene Thermal Maximum.
At the time of its discovery Lazarussuchus was considered an example of the Lazarus effect because its "unexpected" presence followed a long gap in the choristodere fossil record.