Publications
Osteohistological insight into the growth dynamics of early dinosaurs and their contemporaries
Early dinosaurs from the Ischigualasto Formation exhibited elevated growth rates, comparable to or exceeding those of later Mesozoic sauropodomorphs and theropods. Unlike later dinosaurs, these early species grew more continuously rather than in rapid bursts. This suggests that high growth rates were an ancestral trait for Dinosauria and played a key role in their ecological success, though they did not uniquely set them apart from contemporaries like crocodylomorphs and pseudosuchians.
Primer registro de Oxyrhopus rhombifer bachmanni (Squamata: Dipsadidae) en el Parque Provincial Ischigualasto, San Juan, Argentina
Researchers report the first recorded presence of Oxyrhopus rhombifer bachmanni, a snake species from the Dipsadidae family, within Ischigualasto Provincial Park (PPI), Argentina. This discovery increases the known reptile diversity in the PPI to six snake species and 26 total herpetofauna species. The study builds on prior surveys of mammals, birds, amphibians, and reptiles in this UNESCO-listed site, contributing critical data for conservation and management decisions. By mapping herpetofauna distribution, the research provides actionable insights to protect biodiversity in one of Argentina's most significant natural heritage areas.
Rhexoxylon piatnitzkyi and its ancient adversaries: deciphering plant-beetle interactions and its palaeoecological significance in the Ischigualasto Formation (Upper Triassic, Argentina)
Fossilized evidence from the Ischigualasto Formation reveals ancient interactions between the corystosperm plant Rhexoxylon piatnitzkyi and wood-boring beetles, likely early cerambycids. CT scans and thin sections exposed abundant galleries in branches, targeting secondary phloem and pith, while trunks showed fewer borings. The presence of fungal decay and tracheid fragments in frass suggests the beetle fed on both living and decayed wood. Anatomical features indicate the plant may have deployed defenses against both fungi and insects. This is the first record of insect galleries in corystosperm axes, offering insights into Triassic Gondwanan ecosystems.
Paleoneurology and neuroanatomical notes on the South American “rauisuchian” Saurosuchus galilei from the Ischigualasto formation, San Juan, Argentina
A groundbreaking paleoneurological study of Saurosuchus galilei, a large Triassic predator from Argentina's Ischigualasto Formation, reveals that this 'rauisuchian' possessed an exceptionally acute sense of smell, surpassing expectations for its body size. This enhanced olfactory ability, akin to modern crocodilians and tyrannosaurid dinosaurs, suggests it relied on scent to track prey over long distances, compensating for weaker vision and balance. Researchers identified unique pharyngotympanic pneumaticity in the braincase and detailed structures like cranial nerves (V-XII), olfactory bulbs, blood vessels, and inner ear using natural casts and digital endocasts. The study challenges traditional views of rauisuchian sensory capabilities and provides insights into their ecological role before the rise of theropod dinosaurs.
Araucariaceous fossil woods from the Upper Triassic Ischigualasto Formation (San Juan Province, Argentina): paleofloristic and paleoclimatic implications
A new species of fossil wood, Agathoxylon argentinum, has been identified from the Upper Triassic Ischigualasto Formation in Argentina. This discovery, preserved as silica permineralization, reveals unique anatomical features distinct from other Mesozoic Gondwanan species, linking it to the conifer family Araucariaceae. The study also documents fungal-mediated wood decay and spherical structures interpreted as holocarpic chytrid fungi, providing insights into paleoecological processes. Analysis of growth rings suggests that A. argentinum was an evergreen gymnosperm, thriving in humid conditions. Additionally, the research highlights a significant floristic change in the Ischigualasto Formation, marked by the decline of corystosperm genera and increased humidity, offering new paleoclimatic implications for this UNESCO-listed site.
An enigmatic new archosauriform from the Carnian-Norian Ischigualasto Formation of Northwestern Argentina
Researchers have uncovered Incertovenator longicollum, an enigmatic new archosauriform from the Carnian-Norian Ischigualasto Formation in northwestern Argentina. This discovery sheds light on the evolutionary diversity of Late Triassic archosaurs, with its elongated cervical vertebrae presenting a unique combination of traits found in early avemetatarsalian and pseudosuchian clades. Phylogenetic analyses place Incertovenator within Archosauria, either as an early diverging avemetatarsalian or loricatan, closely related to Aphanosauria, Ornithodira, or Mandasuchus tanyauchen. The study highlights convergent evolution in neck elongation across multiple Triassic archosauriform clades, providing new insights into the morphological and phylogenetic complexity of this pivotal period in vertebrate history.
Anatomical Details of Aetosauria (Archosauria: Pseudosuchia) as Revealed by an Articulated Posterior Skeleton from the Upper Triassic Ischigualasto Formation, San Juan Province, Argentina
Researchers have uncovered significant anatomical details of Aetosauria, a group of early-diverging 'crocodile-line' archosaurs, through the study of an articulated posterior skeleton from the Upper Triassic Ischigualasto Formation in Argentina. The specimen, resembling but not definitively assignable to the genus Aetosauroides, reveals unique features such as robust body structure and a distinct tail morphology. Notably, it displays extensive appendicular armor and a well-preserved caudal ventral carapace, which consists of only two columns of ventral osteoderms and includes a large cloacal vent. The study also identifies a fusion of posterior ventral paramedian osteoderms into a single element, a previously undocumented characteristic in aetosaurs. These findings challenge existing understanding of aetosaur anatomy and paleobiology.
Dicroidium (Zuberia) zuberi (Szajnocha) Archangelsky from exceptional Carnian leaf litters of the Ischigualasto Formation, westernmost Gondwana
Exceptional leaf litters from the Carnian Ischigualasto Formation, Argentina, reveal remarkable phenotypic plasticity in the fern-like plant Dicroidium (Zuberia) zuberi. Unlike previous hypostomatic records, these specimens exhibit thick, amphistomatic cuticles with sunken, randomly distributed stomata and papillae on epidermal cells, suggesting adaptability to environmental conditions. The study leveraged optical and scanning electron microscopy to analyze autochthonous or parauchthonous leaf accumulations preserved in abandoned fluvial channels, which also provided insights into the region's seasonal climate and post-biotic turnover (228.91 Ma). Palynological data further supports a humid environment that fostered this diverse vegetation after significant ecological changes.
Skull osteology of the holotype of the rhynchosaur Hyperodapedon sanjuanensis (Sill, 1970) from the Upper Triassic Ischigualasto Formation of Argentina
A groundbreaking study reveals the first detailed three-dimensional reconstruction of a rhynchosaurid palate, significantly advancing our understanding of these distinctive Triassic herbivores. The research, focusing on the holotype skull of Hyperodapedon sanjuanensis from Argentina's Ischigualasto Formation, utilized repreparation and computed tomography (CT) scanning to uncover novel anatomical features, including the presence of septomaxillae bones—a first for rhynchosaurids. This discovery not only provides critical insights into the complex masticatory apparatus of rhynchosaurs but also sheds light on their evolutionary trajectory, offering a more comprehensive view of their morphological diversity and taxonomic relationships in South America.
A Review of Vertebrate Beak Morphologies in the Triassic; A Framework to Characterize an Enigmatic Beak from the Ischigualasto Formation, San Juan, Argentina
A unique fossil beak (PVSJ 427) from the Late Triassic Ischigualasto Formation, Argentina, provides insight into early beak evolution and ecological convergence. The iron-rich cast fossil, triangular with a concave midline shelf, lacks clear synapomorphies but resembles ornithischian dinosaur predentaries, suggesting an early evolutionary origin of this structure. Researchers analyzed phylogenetic distribution and morphology of Triassic beaks to create a framework for estimating beak similarity, placing PVSJ 427 alongside other vertebrate clades from the period. This study advances understanding of edentulous dietary modifications in early reptiles and their ecological implications, indicating that the animal bearing PVSJ 427 was ecologically convergent with the earliest ornithischian dinosaurs.
Confirmación de la presencia de pecarí de collar (Pecari tajacu) en el Parque Provincial Ischigualasto (San Juan, República Argentina)
Research confirms the presence of the collared peccary (Pecari tajacu) in Ischigualasto Provincial Park, Argentina. This finding extends the known distribution of the species, contributing to understanding its ecological range within UNESCO-listed sites. The study employed field observations and ecological data analysis to document the species' occurrence, behavior, and habitat use. Published in Notas Sobre Mamíferos Sudamericanos, this work highlights the importance of monitoring mammal populations in protected areas.
El impacto económico del turismo en localidades pequeñas. Análisis insumo-producto aplicado a los parques Ischigualasto y Talampaya
A study on the UNESCO World Heritage Sites of Ischigualasto and Talampaya Natural Parks in Argentina reveals that increased tourist demand correlates positively with local economic growth, particularly in small communities like Valle Fértil-Villa Unión. Researchers used a hybrid insumo-producto interregional model to overcome data scarcity at the subnational level, combining location coefficients with local surveys from 2015-2016. Simulations showed that while tourism boosts local products, this impact could be amplified by developing regional value chains. The findings underscore the potential for sustainable economic development in small, tourism-dependent regions through strategic investments.
Fluvial architecture and paleoenvironmental evolution of the Los Colorados Formation (Norian): Postrift stage of the Ischigualasto–Villa Unión Basin, NW Argentina
A shift from axial to transverse drainage systems played a central role in the postrift basin filling of the Ischigualasto–Villa Unión Basin during the Norian stage. This finding challenges the traditional view that axial systems are the primary sediment feeders in such basins. Researchers analyzed fluvial architecture and paleoenvironmental evolution using facies analysis, architectural-element evaluation, and vertical stacking patterns across 11 stratigraphic intervals of the Los Colorados Formation. The study revealed changes in channel facies concentration, paleocurrents, and sediment provenance, indicating a transition from an axial to a transverse drainage system. This radial pattern in paleocurrent data suggests that transverse systems can significantly influence postrift basin evolution, as evidenced by modern examples.
Los Baldecitos (San Juan, Argentina) como portal del Parque Provincial Ischigualasto (Patrimonio de la Humanidad) : puesta en valor del patrimonio cultural tangible e intangible
Los Baldecitos, a locality adjacent to the UNESCO-listed Ischigualasto / Talampaya Natural Parks in Argentina, holds significant untapped potential for sustainable tourism development. The study identifies key tangible and intangible cultural heritage assets that could attract visitors, while highlighting critical challenges such as inadequate maintenance of sites, lack of institutional support, and the lingering effects of the COVID-19 pandemic. Despite being part of one of Argentina's most visited protected areas, Los Baldecitos fails to benefit from its proximity due to limited local initiatives and infrastructure. The research underscores the need for community-driven projects, supported by subsidies and technical assistance, to capitalize on the region's heritage and align with global trends toward sustainable tourism.
The Late Triassic Ischigualasto Formation at Cerro Las Lajas (La Rioja, Argentina): fossil tetrapods, high-resolution chronostratigraphy, and faunal correlations
A new high-resolution chronostratigraphic framework for the Late Triassic Ischigualasto Formation at Cerro Las Lajas, Argentina, reveals that rhynchosaur-dominated faunas persisted into the earliest Norian. The study, combining detailed lithostratigraphy and U-Pb geochronology from three intercalated tuffs, constrains the formation's deposition between 230.2 ± 1.9 Ma and 221.4 ± 1.2 Ma, with its fossil-bearing interval dated to 229.20 + 0.11/- 0.15-226.85 + 1.45/- 2.01 Ma. This precise dating allows for biostratigraphic correlations across South American basins and provides a ca. 229 Ma age assignment to the ornithischian Pisanosaurus mertii, partially filling a ghost lineage in early dinosaur evolution. The research also introduces two new biozones, the Hyperodapedon and Teyumbaita, based on rhynchosaur ranges.
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