Pronunciation: kris-TAY-tuh-SOR-rus
Meaning: Crested lizard
Author/s: Taquet and Russell (1998)
Synonyms: Suchomimus tenerensis?
First Discovery: Tenere desert, Niger
Discovery Chart Position: #423
Cristatusaurus lapparenti
Cristatusaurus lapparenti is one of those enigmatic dinosaurs that seems to hover in the taxonomic twilight zone. Discovered in the Elrhaz Formation of Niger and formally named in 1998, it was originally identified as an indeterminate species of Baryonyx sp (Baryonyx sp.)—a tentative assignment based on fragmentary jaw material that bore striking resemblance to the English spinosaurid Baryonyx walkeri. The fossils included parts of the snout tip and lower jaw, with conical teeth and a long, narrow snout—classic hallmarks of the fish-eating baryonychines. But when Philippe Taquet and Dale Russell published their findings, they opted to give the animal its own genus, citing minor distinctions such as the shape of the snout crest, for which it was named.
Since then, Cristatusaurus has remained a taxonomic question mark. The material is sparse and overlaps heavily with that of Suchomimus tenerensis, another spinosaurid named just two months later from the same formation. Some researchers argue that Cristatusaurus and Suchomimus are actually the same animal, and if so, Cristatusaurus would technically have naming priority. Others go further, suggesting that Cristatusaurus might not be distinct from Baryonyx at all, and that the original identification as Baryonyx sp. may have been more accurate than the later reassignment. These views remain in the minority, but they highlight the difficulty of drawing firm lines between taxa when the fossil record is fragmentary and anatomical differences are subtle.
Cristatusaurus belongs to the Spinosauridae, a family of theropod dinosaurs known for their conical teeth, elongated crocodile-like snouts, and a shared fondness for fish. Within this family, the Baryonychinae sub-group includes genera like Baryonyx, Suchomimus, and potentially Cristatusaurus. Although spinosaurids, spinosaurines and baryonychines share a broadly similar body plan—bipedal stance, robust forelimbs, and three-fingered hands with an enlarged first-digit claw—they differ in proportions and adaptations. Spinosaurines, such as Spinosaurus, evolved more extreme aquatic traits, including retracted nostrils and tall neural spines forming prominent back sails. In contrast, baryonychines typically had lower sails or none at all and retained more conventional theropod features, suggesting a lifestyle closely tied to shorelines and shallow waterways, but primarily terrestrial in nature.
Since then, Cristatusaurus has remained a taxonomic question mark. The material is sparse and overlaps heavily with that of Suchomimus tenerensis, another spinosaurid named just two months later from the same formation. Some researchers argue that Cristatusaurus and Suchomimus are actually the same animal, and if so, Cristatusaurus would technically have naming priority. Others go further, suggesting that Cristatusaurus might not be distinct from Baryonyx at all, and that the original identification as Baryonyx sp. may have been more accurate than the later reassignment. These views remain in the minority, but they highlight the difficulty of drawing firm lines between taxa when the fossil record is fragmentary and anatomical differences are subtle.
Cristatusaurus belongs to the Spinosauridae, a family of theropod dinosaurs known for their conical teeth, elongated crocodile-like snouts, and a shared fondness for fish. Within this family, the Baryonychinae sub-group includes genera like Baryonyx, Suchomimus, and potentially Cristatusaurus. Although spinosaurids, spinosaurines and baryonychines share a broadly similar body plan—bipedal stance, robust forelimbs, and three-fingered hands with an enlarged first-digit claw—they differ in proportions and adaptations. Spinosaurines, such as Spinosaurus, evolved more extreme aquatic traits, including retracted nostrils and tall neural spines forming prominent back sails. In contrast, baryonychines typically had lower sails or none at all and retained more conventional theropod features, suggesting a lifestyle closely tied to shorelines and shallow waterways, but primarily terrestrial in nature.
(Lapparent's Crested Lizard)Etymology
Cristatusaurus is derived from the Latin "cristatus" (crested) and the Greek "sauros" (lizard), in reference to its crested snout.
The species epithet, lapparenti (lap-a-REN-tie), honours Albert Felix de Lapparent [1905-1975] for his contributions to the knowledge of Saharan dinosaurs, and his generous assistance during the field season of 1966.
Discovery
The first remains of Cristatusaurus were discovered in the the Elrhaz Formation at the GAD-5 locality, Gadoufaoua (In the language of Touareg: "the place where camels fear to go"), Agadez, Niger, by Philippe Taquet in 1973.
The holotype (MNHN GDF 366), consists of 3 snout bones and a portion of lower jaw.
Referred specimens include MNHN GDF 365 (a pair of bones from the tip of the upper jaw) and MNHN GDF 357—359 and 361 (four parts of back vertebrae). Two thumb claws have also been assigned to Cristatusaurus.
