Herbstosaurus Pigmaeus

''Herbstosaurus'' (meaning "Herbst lizard") is an extinct genus of pterosaurs that lived during the late Jurassic period in what is now Argentina. The genus contains a single species, ''H. pigmaeus'', known from a partial skeleton. The specimen was initially identified as belonging to a small theropod dinosaur, but was later recognized as belonging to a pterosaur.

History

In 1969, Argentine paleobotanist Rafael Herbst dug up a piece of sandstone Neuquén Province at Picun Leufú, containing a number of disarticulated bones of a small reptile. At the time it was assumed the rock dated to the Middle Jurassic (Callovian), about 163 million years ago.

In 1975, paleontologist Rodolfo Magín Casamiquela named the find as a new genus and species, ''Herbstosaurus pigmaeus''.Casamiquela, R. M. (1975). ''Herbstosaurus pigmaeus'' (Coeluria, Compsognathidae) n. gen. n. sp. from the Middle Jurassic of Neuquén (northern Patagonia). One of the smallest known dinosaurs. ''Actas del Primer Congreso Argentino de Paleontologia y Bioestratigrafia, Tucumán'' 2:87-103 The genus name honours Herbst and connects his name to Greek ''sauros'', "lizard", a usual element in the name of dinosaurs. The specific name is derived from Greek ''pygmaios'', "dwarf", as it was thought the form represented a small ''Compsognathus''-like coelurosaurian theropod belonging to the Coeluridae and one of the smallest dinosaurs then known.

The holotype is CTES-PZ-1711, consisting of a sacrum, pelvic elements, and both femora preserved within a sandstone nodule which also contains an ammonite identified in 2025 as ''cf. Lytohoplites alternans''. The dispersed bones are compressed, crushed by the weight of the layers above. Casamiquela had already indicated that the new species was very distinct because of an atypically long ilium and short ischium. In 1978, while reviewing the relations of ''Compsognathus'', John Ostrom concluded that these qualities were best explained if ''Herbstosaurus'' was not a dinosaur but a pterosaur, for which such proportions are typical. The new identification allowed some fragmentary pterosaur material found in the same layers to be referred to ''Herbstosaurus'', including a wing bone.

Classification

Historically, determining the phylogenetic position of ''Herbstosaurus'' has been complicated. José Bonaparte and John Ostrom placed ''Herbstosaurus'' within Pterosauria in 1978 and 1980. In 1981, Peter Galton stated it was a member of the Pterodactyloidea. In his 1988 general textbook on vertebrate paleontology, Robert Carroll narrowed that down to the Pterodactylidae. However, in 1991, Peter Wellnhofer suggested it was not a pterodactyloid but a more basal pterosaur, because of the form of the pelvis. In 1996, David Unwin concluded ''Herbstosaurus'' was a basal member of the Dsungaripteroidea. This was again doubted by Laura Codorniú and Zulma Gasparini in 2007.Codorníu, L. & Gasparini Z. (2007). Pterosauria. In: Gasparini, Z., Salgado, L. & Coria, R. (Eds), Patagonian Mesozoic Reptiles. Indiana University Press, ''Bloomington and Indianapolis, Indiana'', p. 143-166.

In 2025, Ezcurra et al. reanalysed the ''Herbstosaurus'' holotype. While the specimen is fragmentary, they were able to score it in a phylogenetic dataset to test its relationships and affinities with other pterosaurs. Based on the anatomy of its femur, they recovered ''Herbstosaurus'' as a member of the Dsungaripteroidea, deeply nested within Pterodactyloidea. Their results are displayed in the cladogram below:

See also

* List of pterosaur genera
* Timeline of pterosaur research

References

{{Portal bar, Paleontology, Argentina

Pterodactyloidea
Tithonian life
Late Jurassic pterosaurs of South America
Jurassic Argentina
Fossils of Argentina
Neuquén Basin
Fossil taxa described in 1974