Eichstaettisaurus can be identified by flattened skulls with short, blunt, and rounded snouts.
E. schroederi had large nostrils.
The tooth-bearing bones of the snout, the premaxilla and the maxilla, were likely connected by a band of soft tissue in E. schroederi.
The premaxilla had 6 or 7 teeth in E. gouldi, but the number in E. schroederi is unknown; the maxilla had approximately 22 teeth in E. schroederi, and at least 30 in E. gouldi.
The teeth of both species were small, narrow, conical, and single-cusped; they had a pleurodont implantation, meaning that they were fused to the inner side of the jawbone.
Like Ardeosaurus, both species lacked the lacrimal bone, usually a part of the eye socket.
Also in the eye socket, the postfrontal and postorbital bones were separate unlike Ardeosaurus, and the rearward projection of the latter bones were relatively wide.
In E. schroederi, the contact between these bones was further forward than most lizards.
The squamosal bones were slender and projected downwards to meet the quadrate bones, as in most lizards; unlike the Iguania and Teiidae, however, they lacked upward projections.
Living geckoes lack the postorbital and squamosal bones, and they also have relatively shorter jugal bones than Eichstaettisaurus.
On the palate of E. schroederi, the ectopterygoid bones overlapped the pterygoid bones at their rear.

Unlike A. brevipes, E. schroederi lacked bone ornamentation and osteoderms on the skull roof.
In both species, the frontal bones were fused and narrower between the eye sockets than they were at the front.
The downward projections on the frontals known as subolfactory processes were well-developed in both species, but met at the midline only in E. schroederi.
The suture between the frontal and parietal bones was convex in E. schroederi and concave in E. gouldi, unlike Ardeosaurus where it was straight.
E. gouldi and most other lizards have fused parietal bones, but they were paired and unfused in E. schroederi.
The parietals of both species lacked rearward projections and nuchal fossae.
In E. schroederi, the outer edges of the parietals curved inwards, and the rearward projections known as the supratemporal processes were short, widely separated, and bore depressions.
Also in E. schroederi, a pair of crests were present on the supraoccipital bone of the braincase, which were likely imprinted by the semicircular canals due to the skull's reduced ossification.
Eichstaettisaurus can be identified by flattened skulls with short, blunt, and rounded snouts. E. schroederi had large nostrils. The tooth-bearing bones of the snout, the premaxilla and the maxilla, were likely connected by a band of soft tissue in E. schroederi. The premaxilla had 6 or 7 teeth in E. gouldi, but the number in E. schroederi is unknown; the maxilla had approximately 22 teeth in E. schroederi, and at least 30 in E. gouldi. The teeth of both species were small, narrow, conical, and single-cusped; they had a pleurodont implantation, meaning that they were fused to the inner side of the jawbone. Like Ardeosaurus, both species lacked the lacrimal bone, usually a part of the eye socket. Also in the eye socket, the postfrontal and postorbital bones were separate unlike Ardeosaurus, and the rearward projection of the latter bones were relatively wide. In E. schroederi, the contact between these bones was further forward than most lizards. The squamosal bones were slender and projected downwards to meet the quadrate bones, as in most lizards; unlike the Iguania and Teiidae, however, they lacked upward projections. Living geckoes lack the postorbital and squamosal bones, and they also have relatively shorter jugal bones than Eichstaettisaurus. On the palate of E. schroederi, the ectopterygoid bones overlapped the pterygoid bones at their rear.
Unlike A. brevipes, E. schroederi lacked bone ornamentation and osteoderms on the skull roof. In both species, the frontal bones were fused and narrower between the eye sockets than they were at the front. The downward projections on the frontals known as subolfactory processes were well-developed in both species, but met at the midline only in E. schroederi. The suture between the frontal and parietal bones was convex in E. schroederi and concave in E. gouldi, unlike Ardeosaurus where it was straight. E. gouldi and most other lizards have fused parietal bones, but they were paired and unfused in E. schroederi. The parietals of both species lacked rearward projections and nuchal fossae. In E. schroederi, the outer edges of the parietals curved inwards, and the rearward projections known as the supratemporal processes were short, widely separated, and bore depressions. Also in E. schroederi, a pair of crests were present on the supraoccipital bone of the braincase, which were likely imprinted by the semicircular canals due to the skull's reduced ossification.
Eichstaettisaurus