Article
Multidisciplinary Sciences
Min Wang, Thomas A. Stidham, Zhiheng Li, Xing Xu, Zhonghe Zhou
Summary: The study describes a new enantiornithine bird from the Early Cretaceous in China, revealing the components of cranial kinesis and highlighting the highly modular and mosaic evolution of avialan skulls. Early birds not only had major innovations in their locomotor system, but also evolved highly derived skulls.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Walter Scott Persons, Hallie P. Street, Amanda Kelley
Summary: Serpentisuchops pfisterae is an Upper Cretaceous plesiosaur with both elongated snout and elongated neck features. Its long snout is an ancestral trait, while its long neck is secondarily derived and similar to other related species. It has a piscivorous diet and likely used its neck and snout in fast lateral strikes.
Article
Multidisciplinary Sciences
Attila Osi, Janos Magyar, Karoly Rosta, Matthew Vickaryous
Summary: This study provides new details on the cranial anatomy of the nodosaurid Hungarosaurus, identifying three different size classes representing various ontogenetic stages. The well-developed cranial ornamentation in early ontogenetic stages suggests a potential role in intra- and interspecific recognition. The observed variation in cranial ornamentation in Hungarosaurus appears to be associated with development, rather than the contribution of coossified osteoderms.
Article
Multidisciplinary Sciences
Demian A. Nelson, John M. Cottle, Ilya N. Bindeman, Alfredo Camacho
Summary: The Butcher Ridge Igneous Complex in the Early Jurassic period contains glass with high water content and low hydroxyl component, indicating secondary hydration. The glass also has the most depleted hydrogen isotopes ever measured in terrestrial rocks, suggesting it was hydrated by polar glacial ice and melt water during the Late Cretaceous, contradicting previous reconstructions of an ice-free Antarctica in a global hot greenhouse.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Chinzorig Tsogtbaatar, Thomas Cullen, George Phillips, Richard Rolke, Lindsay E. Zanno
Summary: Studying the evolution and diversity of Late Cretaceous dinosaur assemblages in North America requires continuous spatiotemporal data. However, there is a spatial and temporal disparity in the dinosaur data on the continent. This study describes an assemblage of ornithomimosaurian fossils from the Santonian Eutaw Formation in Mississippi. The results suggest the presence of two different-sized taxa, including one of the largest known ornithomimosaurians worldwide. These findings provide key information on the diversity and distribution of North American ornithomimosaurs and indicate the coexistence of multiple species of ornithomimosaurs in the Late Cretaceous ecosystems of Laurasia.
Article
Biology
Min Wang, Thomas A. Stidham, Jingmai K. O'Connor, Zhonghe Zhou
Summary: Cranial kinesis, the independent movements and flexibility of different parts of the skull, is an evolutionary innovation found in some squamates and crown birds. It plays a major role in the phenotypic and ecological diversity of birds. However, the understanding of the evolutionary development of cranial kinesis in early avialans is hindered by sparse fossil records. A detailed reconstruction of the skull of the Early Cretaceous enantiornithine Yuanchuavis kompsosoura provides insights into the mosaic assembly of features required for modern cranial kinesis in birds.
Article
Multidisciplinary Sciences
Yann Rollot, Serjoscha W. Evers, Richard L. Cifelli, Walter G. Joyce
Summary: In this study, the skull of Lakotemys australodakotensis is described using micro-computed tomography. Preliminary comparisons show that it shares similar cranial anatomy with Arundelemys dardeni and possesses a combination of features found in both baenids and non-baenid paracryptodires. Furthermore, it is the only known baenid to possess a canal for the palatine artery.
Article
Multidisciplinary Sciences
Lindsay E. Zanno, Terry A. Gates, Haviv M. Avrahami, Ryan T. Tucker, Peter J. Makovicky
Summary: Intensifying macrovertebrate reconnaissance and age-dating techniques in recent decades have provided a more detailed understanding of the impact of the Cretaceous Thermal Maximum on terrestrial ecosystems. A new early-diverging ornithopod, Iani smithi gen. et sp. nov., has been discovered in Utah, USA, adding to the knowledge of Cretaceous fauna. This finding confirms the coexistence of at least five neornithischian clades in the earliest Late Cretaceous terrestrial ecosystems of North America.
Article
Multidisciplinary Sciences
Carla Bardua, Anne-Claire Fabre, Julien Clavel, Margot Bon, Kalpana Das, Edward L. Stanley, David C. Blackburn, Anjali Goswami
Summary: The study reveals that skull morphology in frogs is mainly influenced by factors such as skull size, microhabitat, and developmental stages, with late-ossifying elements evolving at the fastest rates. Different microhabitat types occupy distinct regions in morphospace, displaying rapid evolution and high disparity.
NATURE COMMUNICATIONS
(2021)
Article
Biology
Nicolas R. Chimento, Federico L. L. Agnolin, Makoto Manabe, Takanobu Tsuihiji, Thomas H. H. Rich, Patricia Vickers-Rich, Fernando E. E. Novas
Summary: A tooth from the Late Cretaceous in Argentina suggests the presence of monotremes in South America at the end of the Mesozoic Era. Monotremata, a group of egg-laying mammals represented by the platypus and echidnas, is endemic to Australia and nearby islands. The discovery of a Late Cretaceous monotreme in southern Argentina indicates their presence in circumpolar regions and suggests that their distinctive anatomical features were already present in ancient forms.
COMMUNICATIONS BIOLOGY
(2023)
Article
Multidisciplinary Sciences
Serjoscha W. Evers, Yann Rollot, Walter G. Joyce
Summary: Arundelemys dardeni is an Early Cretaceous paracryptodire with an important role in understanding the early evolution of Baenidae and Paracryptodira. The initial anatomical description of the species was found to have errors, which were corrected based on computer tomography scans. Additionally, novel anatomical information was provided, highlighting features of the cranial bones, endosseous labyrinth, and cranial scutes.
Article
Biology
Christopher J. Mayerl, Rebecca Z. German
Summary: This article synthesizes the research on maternal and infant function, discussing the origin and diversification of lactation and suckling. The authors argue that while there is extensive research on maternal function, there is a lack of exploration on the diversity of infant function, which needs to be addressed in future studies.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2023)
Article
Multidisciplinary Sciences
Yann Rollot, Serjoscha W. Evers, Stephanie E. Pierce, Walter G. Joyce
Summary: This study utilizes micro-computed tomography to analyze the skull of an Early Cretaceous baenid turtle, providing new insights into its cranial anatomy and the evolutionary relationship with other baenid and paracryptodire species.
Article
Multidisciplinary Sciences
Leif Moritz, Elena Borisova, Joerg U. Hammel, Alexander Blanke, Thomas Wesener
Summary: This study reports the use of a sucking pump for fluid feeding in the arthropod class Diplopoda. The findings show that these millipedes have a pumping chamber similar to that of insects, indicating convergent evolution in the biomechanical solution for fluid feeding across major arthropod taxa. Fluid feeding is an important evolutionary innovation in terrestrial arthropods, and further research is needed to understand why certain lineages, such as Colobognatha, have fewer species compared to fluid-feeding insects.
Article
Multidisciplinary Sciences
Xiaoming Wang, Denise F. Su, Nina G. Jablonski, Xueping Ji, Jay Kelley, Lawrence J. Flynn, Tao Deng
Summary: The giant panda has an extra thumb for bamboo manipulation and weight distribution, but it has not evolved further since its early existence, possibly due to the need for balance while walking.
SCIENTIFIC REPORTS
(2022)
Article
Evolutionary Biology
Luis Ossa-Fuentes, Sergio Soto-Acuna, Paula Bona, Michel Sallaberry, Alexander O. Vargas
Summary: In the evolution from dinosaurs to birds, the avian ankle underwent significant changes. By studying embryos of birds, crocodiles, and iguanas, it was discovered that the formation of the avian ankle is a result of the fusion of earlier cartilages. Throughout the transition from dinosaurs to birds, the embryonic cartilage dt2 was consistently present.
JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION
(2022)
Article
Geology
Rodrigo A. Otero, Sergio Soto-Acun
Summary: A partial postcranial skeleton of an elasmosaurid plesiosaur recovered from central Chile is described as a new aristonectine, being the second representative of this clade known in the southeastern Pacific during the late Maastrichtian. This new taxon is recovered as a basal aristonectine in phylogenetic analysis, possessing unique morphology intermediate between non-aristonectine Weddellian elasmosaurids and aristonectines.
CRETACEOUS RESEARCH
(2021)
Article
Geology
David Rubilar-Rogers, Alexander O. Vargas, Bernardo Gonzalez Riga, Sergio Soto-Acuna, Jhonatan Alarcon-Munoz, Jose Iriarte-Diaz, Carlos Arevalo, Carolina S. Gutstein
Summary: A new lithostrotian sauropod, Arackar licanantay gen. et sp. nov., has been discovered in the Upper Cretaceous beds of the Hornitos Formation in Atacama Region, northern Chile. This new titanosaur exhibits unique characteristics and is phylogenetically classified in a clade with Rapetosaurus and Isisaurus. It is the third dinosaur named from Chile and the third titanosaur from the western side of the Andes in South America.
CRETACEOUS RESEARCH
(2021)
Article
Multidisciplinary Sciences
Agustin G. Martinelli, Sergio Soto-Acuna, Francisco J. Goin, Jonatan Kaluza, J. Enrique Bostelmann, Pedro H. M. Fonseca, Marcelo A. Reguero, Marcelo Leppe, Alexander O. Vargas
Summary: This study describes a new meridiolestidan mammal, Orretherium, from the Late Cretaceous of southern Chile, based on a partial jaw and an isolated upper premolar. Phylogenetic analysis suggests Orretherium is the earliest divergence within Mesungulatidae, potentially hinting at the presence of multiple species within the family. The study sheds light on the heterochronic tooth eruption pattern in meridiolestidans compared to basal dryolestoids, providing important insights into mammalian evolution during the Mesozoic Era.
SCIENTIFIC REPORTS
(2021)
Article
Geology
Jhonatan Alarcon-Munoz, Laura Codorniu, Edwin Gonzalez, Mario E. Suarez, Manuel Suarez, Omar Vicencio-Campos, Sergio Soto-Acuna, Jonatan Kaluza, David Rubilar-Rogers, Alexander O. Vargas
Summary: We have discovered ctenochasmatid pterosaurs fossils in Cerro Tormento, Cerros Bravos, Northern Chile. The fossils include cervical vertebrae, scapula, humerus, femur, and tibiotarsus impressions. These findings suggest that Ctenochasmatidae was widespread in northern Chile and Cerro Tormento may have been a pterosaur colony.
CRETACEOUS RESEARCH
(2022)
Article
Geology
Rodrigo A. Otero, Mario E. Suarez
Summary: This study presents new material of ray-finned fishes from Upper Cretaceous strata in central Chile, including specimens of the genus Enchodus and teeth of Pachyrhizodus and indeterminate pachycormids. It provides a critical review of historical ray-finned fishes in the region and suggests that the latest Cretaceous actinopterygian diversity along the southeastern Pacific was more discrete and scarce than previously thought.
CRETACEOUS RESEARCH
(2022)
Article
Multidisciplinary Sciences
Sergio Soto-Acuna, Alexander O. Vargas, Jonatan Kaluza, Marcelo A. Leppe, Joao F. Botelho, Jose Palma-Liberona, Carolina Simon-Gutstein, Roy A. Fernandez, Hector Ortiz, Veronica Milla, Barbara Aravena, Leslie M. E. Manriquez, Jhonatan Alarcon-Munoz, Juan Pablo Pino, Cristine Trevisan, Hector Mansilla, Luis Felipe Hinojosa, Vicente Munoz-Walther, David Rubilar-Rogers
Summary: Armoured dinosaurs from southern Gondwana are rare, but important in understanding the evolution of Ankylosauria. The discovery of the unique tail weapon in Stegouros elengassen sheds light on the early branching of ankylosaurs in Gondwana. Phylogenetic analyses show that Stegouros is related to Kunbarrasaurus from Australia and Antarctopelta from Antarctica, forming a distinct clade of Gondwanan ankylosaurs.
Article
Geosciences, Multidisciplinary
Juan Pablo Guevara, Felipe Suazo E. Lara, Jhonatan Alarcon-Munoz, Karina E. Buldrini, Sergio Soto-Acuna, David Rubilar-Rogers
Summary: This study describes the first fossil record of an ancient anuran from the Neogene era in Chile, which shares similarities with extant members of the Rhinella genus. The discovery represents the southernmost Bufonidae fossil record in South America for the Miocene epoch.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2022)
Article
Multidisciplinary Sciences
Rodrigo A. Otero
Summary: This contribution presents novel records of ray-finned fishes from the Oxfordian of Cerritos Bayos, northern Chile, including new diversity of Pachycormiformes and the first Upper Jurassic local record of a Lepisosteidae. These new records expand the known actinopterygian diversity from the Upper Jurassic of southeastern Panthalassa.
Article
Geosciences, Multidisciplinary
Rodrigo A. Otero, David Rubilar-Rogers, Sergio Soto-Acuna, Alexander M. Vargas, Gonzalo Mella Rojas, Raul Ugalde, Osvaldo Rojas, Jennyfer Rojas, Fernando E. Novas
Summary: This contribution reveals new vertebrate remains found in Triassic strata in the Atacama Desert, northern Chile. These include the first temnospondyl record in the El Bordo Basin, as well as actinopterygians related to Pseudobeaconiidae and a ray-finned fish with uncertain classification, Guaymayenia paramillensis. The findings suggest a Middle-to-Upper Triassic age for the Estratos El Bordo unit, providing insights into the paleoenvironment of southwestern South America during this time.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2023)
Article
Geosciences, Multidisciplinary
Sarah N. Davis, Sergio Soto-Acuna, Roy A. Fernandez, Jared Amudeo-Plaza, Marcelo A. Leppe, David Rubilar-Rogers, Alexander O. Vargas, Julia A. Clarke
Summary: The end Cretaceous mass extinction resulted in a significant change in biodiversity, leading to the extinction of non-avian dinosaurs. To understand the diversity of dinosaur clades before this event and the recovery of avian dinosaurs, a better understanding of the global fossil record is needed. The recently described fossil record from southern localities, particularly in southern South America, is crucial in accurately assessing dinosaur diversity trends during the late Cretaceous.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2023)
Article
Evolutionary Biology
Hans P. Puschel, Jhonatan Alarcon-Munoz, Sergio Soto-Acuna, Raul Ugalde, Sarah L. Shelley, Stephen L. Brusatte
Summary: This study describes a new fossil of the macraucheniine macraucheniid, Micrauchenia saladensis, from Chile. The specimen includes various skeletal elements and shows consistent features with terrestrial and cursorial locomotion. It is the smallest member of the Macraucheniinae subfamily and shares certain characteristics with other macraucheniines. Phylogenetic analyses confirm its affiliation with the Macraucheniinae subfamily, but its exact placement within the subfamily remains uncertain.
JOURNAL OF MAMMALIAN EVOLUTION
(2023)
Article
Paleontology
Carolina Acosta Hospitaleche, Sergio Soto-Acuna
Summary: This article describes a new cranium of a penguin species from the Late Miocene, found in the Bahia Inglesa Formation in Northern Chile. The specimen exhibits unique characteristics that suggest it may belong to a new species within the Eudypula Bonaparte, 1856 or Spheniscus Brisson, 1760 genus, or possibly a more basal taxon related to them. The size of the specimen is similar to extant Spheniscus species, but smaller than fossil species of Spheniscus. However, due to incomplete material and a lack of comparison with other fossil species, a more accurate assignment cannot be made.
COMPTES RENDUS PALEVOL
(2023)