Illustration of Argentinadraco barrealensis, a newly discovered pterosaur from Patagonia, flying over a prehistoric lake.

Patagonia's Prehistoric Puzzle: Unearthing a Bizarre New Pterosaur

Nico Varela in Science & Nature December 2025 • 3 min read.

"Scientists discover a unique, toothless flying reptile with an unusual lower jaw in Argentina, challenging our understanding of pterosaur feeding habits and evolution."

Pterosaur fossils, though found worldwide, are often incomplete, leaving gaps in our understanding of these ancient flying reptiles. These specimens predominantly originate from coastal or marine environments, making inland discoveries particularly valuable.

Now, a new species, Argentinadraco barrealensis, has been identified from the Upper Cretaceous Portezuelo Formation in Patagonia, Argentina. The unique structure of its lower jaw is prompting scientists to rethink pterosaur feeding behaviors.

This article explores the discovery of this new azhdarchoid pterosaur, detailing its distinctive features and discussing the implications for our understanding of pterosaur evolution and ecology.

Argentinadraco barrealensis: A One-of-a-Kind Jaw

Illustration of Argentinadraco barrealensis, a newly discovered pterosaur from Patagonia, flying over a prehistoric lake.

The fossil material consists of an incomplete, toothless lower jaw collected from the Futalognko site in northwest Neuquén city, Argentina. This location is known for its rich fossil record, offering glimpses into a diverse ancient ecosystem.

The most striking feature of Argentinadraco is its unusual lower jaw. Key characteristics include:

Laterally compressed anterior portion with blunt lateral margins.
A medial sulcus followed by two well-developed mandibular ridges.
A deeper symphysis (the point where the two halves of the lower jaw meet) than any other known azhdarchoid.
Small dentary sagittal crest.

This unique jaw structure suggests a complex interlocking mechanism with the upper jaw, hinting at specialized feeding adaptations not seen in other pterosaurs.

Rethinking Pterosaur Feeding Strategies

Argentinadraco's unique jaw opens exciting possibilities about pterosaur feeding habits. While speculative, researchers propose that it may have used its lower jaw to cut or plow through soft sediments in shallow waters, potentially preying on invertebrates or crustaceans.

This feeding behavior, previously unconsidered for pterosaurs, suggests a greater ecological diversity within the group than previously recognized. The discovery challenges the assumption that all toothless pterosaurs fed in similar ways.

The discovery of Argentinadraco barrealensis adds a significant piece to the puzzle of South American Cretaceous pterosaurs. While incomplete, this fossil provides valuable new data on the evolution and diversity of azhdarchoid pterosaur jaw morphology, underscoring the importance of continued paleontological research in regions like Patagonia.

About this Article -

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This article is based on research published under:

DOI-LINK: 10.1590/0001-3765201720170478, Alternate LINK

Title: New Azhdarchoid Pterosaur (Pterosauria, Pterodactyloidea) With An Unusual Lower Jaw From The Portezuelo Formation (Upper Cretaceous), Neuquén Group, Patagonia, Argentina

Subject: Multidisciplinary

Journal: Anais da Academia Brasileira de Ciências

Publisher: FapUNIFESP (SciELO)

Authors: Alexander W.A. Kellner, Jorge O. Calvo

Published: 2017-09-25

Everything You Need To Know

What is Argentinadraco barrealensis, and what makes its discovery significant?

Argentinadraco barrealensis, an azhdarchoid pterosaur, was discovered in Patagonia, Argentina. What sets it apart is its unique lower jaw structure, which is toothless, laterally compressed, and features a deep symphysis and distinctive ridges. This suggests a specialized feeding mechanism unlike any other known pterosaur.

Based on its jaw structure, what do scientists think Argentinadraco barrealensis ate?

The prevailing theory is that Argentinadraco barrealensis may have used its unique lower jaw to plow through soft sediments in shallow waters. Scientists believe it potentially preyed on invertebrates or crustaceans. However, without a complete fossil, including the upper jaw, this remains speculative. Further fossil discoveries in the Portezuelo Formation could provide more conclusive evidence about Argentinadraco's diet.

Why is the discovery location of Argentinadraco barrealensis important for understanding pterosaur evolution?

The incompleteness of pterosaur fossil records often leads to gaps in understanding their evolution. Most pterosaur fossils come from coastal regions. Discovering Argentinadraco barrealensis inland offers vital insights into the diversity of pterosaurs and their adaptations to different environments. This also prompts re-evaluating existing evolutionary models.

What are the key features of Argentinadraco barrealensis's lower jaw?

The lower jaw of Argentinadraco barrealensis exhibits several distinct features: a laterally compressed anterior portion, blunt lateral margins, a medial sulcus followed by well-developed mandibular ridges, a deeper symphysis compared to other azhdarchoids, and a small dentary sagittal crest. These characteristics suggest a complex interlocking mechanism with the upper jaw, facilitating unique feeding behaviors.

Where was Argentinadraco barrealensis discovered, and why is this location important for paleontology?

The Futalognko site in northwest Neuquén city, Argentina, where Argentinadraco barrealensis was found, is known for its rich fossil record from the Upper Cretaceous Portezuelo Formation. This geological formation provides a window into a diverse ancient ecosystem. Continued exploration of such sites is crucial to expanding our knowledge of prehistoric life and the evolutionary history of creatures like Argentinadraco and other pterosaurs.