In 1904, local quarrymen discovered the articulated remains of a dog-sized reptile (preserved length is 22 cm) on a dark red-brown sandstone slab in a quarry at Oberbettingen near Hillesheim (Nature- & Geopark Vulkaneifel, Germany). This unique find from the Upper Buntsandstein (Early Triassic, early Anisian, Kyllburg beds) was soon obtained by the local amateur paleontologist Stefan Dohm in Gerolstein, who sent the fossil to Prof. Dr. Ernst Jaeckel for investigation. In the same year, Jaeckel (1904) described the partial skeleton as a new genus and species and called it Eifelosaurus triadicus. The white bones are relatively well preserved. The articulated skeleton is about 60% complete, with the torso and parts of the tail and limbs present. The living animal would have been 50 to 60 cm long (Fig. 1). Jaeckel thought the reptile to be an early lizard but later workers (e.g., Huene 1929; Sander & Gee 1994) saw it otherwise, and Huene (1929) assigned the genus with some confidence to the rhynchosaurs.
Figure 1. Reconstruction of Eifelosaurus triadicus Jaeckel, 1904, exhibited in the Natural History Museum in Gerolstein.
There are only a few papers about Eifelosaurus triadicus. The first was the original article by Jaeckel (1904), who described the type specimen. Huene (1929) revised Jaeckel’s classification and proposed a systematic position within the rhynchosaurids rather than the lizards. Later on, the specimen disappeared. According to Krebs (1969), the fossil remained in the collection of Stefan Dohm in Gerolstein. Unfortunately, this collection was destroyed during World War II, when Gerolstein suffered heavy damage by allied bombers in 1944. However, the Eifelosaurus was fortunately relocated before the destruction (probably after the death of Dohm in 1924) and re-emerged in the collections of the Steinmann Institute in Bonn (Sander & Gee 1994). These authors discussed Eifelosaurus and the few other vertebrate finds from the Buntsandstein in the Eifel, together with a review of the flora and paleoecology of the region in the Lower Triassic. A short note about Eifelosaurus can also be found in Ezcurra et al. (2016), who regard the reptile as a potential early Anisian rhynchosaur and stated that no further studies have been conducted to determine its affinities. According to them, Eifelosaurus would be the oldest of the three known European representatives of Anisian rhynchosaurs, which on a global scale had their main distribution in the Karoo Basin of South Africa with a further occurrence in the Moenkopi Formation of the southwestern USA. The potential for future research appears to be high, and Ezcurra et al. (2016) noted that some undescribed contemporary rhynchosaur material may be present in Germany.
In the Triassic, rhynchosaurs were widely distributed. They are usually easily recognizable by their skull, characterized by a protruding beak (Sander & Gee 1994) used in their herbivorous feeding. In the case of Eifelosaurus, the main problem for a successful systematic assignment is the unknown skull anatomy of the holotype. Additional preparation, coupled with a modern revision of the type specimen might add some further clues. However, according to Sander & Gee (1994), a well-preserved skull would be needed to clarify the systematic position of Eifelosaurus. Unfortunately, no other specimens were found later and a revised determination will have to wait until new material becomes available. This will be difficult that no active quarries in the area of the type locality exist. Even so, modern quarrying would likely not produce more finds because it would need old-style handwork to uncover such rare fossils in the usually more or less sterile sandstones of the Buntsandstein. Another problem could be the unknown exact location of the original quarry (Jaeckel 1904 did not specify a type locality) and the position of the bed in which the reptile has been discovered. There are numerous small and now abandoned quarries in the Kyllburg beds of the Upper Buntsandstein in the area south of Oberbettingen that were used to fulfill local needs for building material, like floor slabs, facades and building stones. The cultural database of Rhineland-Palatinate refers to those quarries (Fig. 2; https://kulturdb.de/einobjekt.php?id=6755) on the slope of the “Wolfskaul” (wolf’s hollow) south of Oberbettingen as the most likely source of the fossil. A label in the exhibition of Eifelosaurus in the Natural History Museum of Gerolstein mentions this site as “Dümmer quarry”.