Thylacocephalans (Euarthropoda: Pancrustacea) are extinct marine pancrustaceans characterised by a folded shield, with fossils known from the Upper Ordovician to the Upper Cretaceous, reaching a diversity peak in the Triassic. We described two new thylacocephalan taxa, Dollocaris toarcica sp. nov. and Zazrivacaris jodorowskyi gen. et sp. nov., from the lower Toarcian, Lower Jurassic black shales of the “Hrýzeň beds” of the Šariš Unit (Grajcarek Succession) exposed in Zázrivá, Slovakia. Thylacocephalans are an accessory element of an euarthropod association, dominated by dendrobranchiate shrimps. This occurrence represents not only the first record of thylacocephalans from Slovakia but also their first formal description from the Toarcian. Dollocaris toarcica sp. nov. is the third described species of its genus, previously known from the Middle Jurassic (Callovian) of France and Upper Jurassic (Tithonian) of Germany, expanding the stratigraphic span of the genus to the Lower Jurassic. The newly described genus Zazrivacaris shows morphological similarities with Mayrocaris, yet another genus known from the Upper Jurassic (Tithonian) of Germany. Considering current knowledge, we present a review of all known micro- and macro-structural patterns present on thylacocephalan shields. These structures appear to be unique to each genus and/or species and are therefore important for taxonomic evaluation.
Francisco J. Muñiz was undoubtedly the first national Argentine paleontologist, preceding Florentino Ameghino with its pioneering descriptions of the fossil bearing beds in Luján and their fossil mammals, including “Muñi-felis”. In 1861, the German naturalist Hermann Burmeister (G. Burmeister, here after) arrived in Argentina to become the Museo Público de Buenos Aires Director. G. Burmeister renovated the institution and founded the Anales del Museo, one of the oldest Argentine scientific publications. In his last years, the Museo de La Plata was consolidated under the leadership of Francisco Pascasio Moreno, who was the creator and served as its Director from 1884 to 1906. Under the direction of Moreno, the museum attracted eminent researchers, including F. Ameghino and his brother Carlos. When the Ameghino brothers left the institution, figures such as Alcides Mercerat and Santiago Roth replaced them. Roth became a key rival to Carlos in exploring Patagonian deposits with vertebrate fossils. F. Ameghino brought global visibility and reconnaissance of the Argentine paleontology due to his numerous publications based on the collections largely made by his brother Carlos and his appointment as the Director of the Museo Nacional de Buenos Aires in 1902. After the death of Florentino, Carlos remained active at this museum, where a new generation of paleontologists emerged. Among them, Lucas Kraglievich stayed briefly in the Museo de La Plata after the death of Roth. Then the Spanish mastozoologist Ángel Cabrera assumed as the Head of Paleontology, marking a notable stage in the Paleontology of Argentina.
Matteo Montagna, Fabio Magnani, Giulia Magoga
et al.
Abstract A fossil attributed to the roachoid family of Subioblattidae, characterized by elongated ellipsoidal forewings and sigmoidal stem of radial vein, is described as Samaroblattella valmarensis sp. nov. The fossil displays a simple subcosta posterior, a long, narrow area posterior to cubitus posterior, with specific wing traits aligning it with Samaroblattella. It differs from Samaroblattella kenderlykensis in the pattern of forewing coloration. The morphology of the hind leg resembles that of the extant jumping cockroach Saltoblattella montistabularis, suggesting a possible jumping behavior, indicative of convergent evolution in Eoblattodea. The elongate ovipositor of this Subioblattidae differs significantly from the reduced ones of the crown group Dictyoptera. Subioblattidae were likely laying their eggs in sediment or plant tissues and did not have hardened ootheca as those in extant lineages. This discovery extends the temporal and geographical range of Samaroblattella, marking it the oldest known representative of the genus and establishing a connection between species from South Africa and Kazakhstan.
Yaqoob Ansari, Mohammed Ishaq, Mohammed Yusuf
et al.
Abstract Understanding ancient organisms and their paleo-environments through the study of body fossils represents a central tenet of paleontology. Advances in digital image capture over the past several decades now allow for efficient and accurate documentation, curation and interrogation of fossil anatomy over disparate length scales. Despite these developments, key body fossil image processing and analysis tasks, such as segmentation and classification still require significant user intervention, which can be labor-intensive and subject to human bias. Recent advancements in deep learning offer the potential to automate fossil image analysis while improving throughput and limiting operator bias. Despite the recent emergence of deep learning within paleontology, challenges such as the scarcity of diverse, high quality image datasets and the complexity of fossil morphology necessitate further advancements and the adoption of concepts from other scientific domains. Here, we comprehensively review state-of-the-art deep learning-based methodologies applied towards body fossil analysis while grouping the studies based on the fossil type and nature of the task. Furthermore, we analyze existing literature to tabulate dataset information, neural network architecture type, key results, and comprehensive textual summaries. Finally, based on the collective limitations of the existing studies, we discuss novel techniques for fossil data augmentation and fossil image enhancements, which can be combined with advanced neural network architectures, such as diffusion models, generative hybrid networks, transformers, and graph neural networks, to improve body fossil image analysis.
Bárbara Vento, Federico Agraín, Gabriela G. Puebla
et al.
The Nothofagus (southern beech) has a rich fossil record and a number of living species distributed exclusively in the Southern Hemisphere. Many attempts have been made to clarify the phylogenetic relationships in Nothofagus but only a few works have included fossil specimens in a phylogenetic framework for a more accurate resolution. Fossil leaves play an important role in deciphering of the evolutionary processes and are a necessary complement in phylogenetic studies. Fossils of Nothofagus have been found in sediments of Antarctica, Australia, New Zealand, New Caledonia, Papua New Guinea, and South America. Here, we performed a phylogenetic analysis including fossils from these areas and examined the character evolution, especially those referred to the morphology of the leaf. Fossil leaves from Antarctica were revised and included in the analysis for the first time. Our results support the monophyly of the four currently recognized subgenera, and novel relationships between extinct and living taxa are discussed. Morphological features of fossil leaves were expressed differently, especially in the teeth shape, size, and secondary venation pattern, when compared to the extant taxa probably related to past climate conditions. The most ancient leaves were recorded in the Upper Cretaceous of Antarctica and placed in subgenera Lophozonia and Fuscospora. Brassospora and Nothofagus are younger clades with distinctive plesiomorphic leaf morphological features. The morphological leaf characters proposed herein, and the inclusion of a considerable number of fossils in our analysis allowed us to provide a study of the evolutionary history of Nothofagus with more precise resolution.
El estudio de los reptiles marinos en Argentina en general, y desde el Museo de La Plata en particular, comenzó con breves
descripciones realizadas por investigadores europeos. A nivel nacional, los primeros estudios datan de fines del siglo XIX y principios del siglo XX. Durante la primera mitad del siglo XX, las contribuciones sobre reptiles marinos desde el Museo de La Plata fueron producto de hallazgos casuales durante prospecciones geológicas y no de exploraciones paleontológicas sistemáticas. En la década de los setenta, esta situación se revirtió a través de un programa de investigación liderado por Zulma Brandoni de Gasparini y desarrollado en el Museo de La Plata, el cual continúa hoy a través de algunos de sus discípulos. A lo largo de los años, en el marco de este programa se prospectaron formaciones marinas mesozoicas en varias provincias de la Argentina y en la Península Antártica. También se formaron recursos humanos, que en la actualidad desarrollan sus investigaciones sobre reptiles marinos mesozoicos tanto en el Museo de La Plata como en otras renombradas instituciones nacionales.
En esta contribución consideramos los ejemplares de anfibios pertenecientes a la colección paleontológica del Museo de La Plata, con énfasis en la importancia de los hallazgos. La mayoría de los ejemplares fueron colectados en localidades fosilíferas en las que se habían descubierto restos de anfibios previamente y con frecuencia durante exploraciones geológicas y campañas para la búsqueda de otros vertebrados. No obstante, la mayoría de los ejemplares de anfibios de esta colección proveen información que mucho ha contribuido a clarificar la evolución de las ramas filogenéticas a las que pertenecen, así como a la composición taxonómica y distribución de las faunas anfibianas de Sudamérica. Los materiales incluyen representantes triásicos de Temnospondyli, Salientia jurásicos y miembros cretácicos y cenozoicos del grupo corona Anura.
Torsten M. Scheyer, Urs Oberli, Nicole Klein
et al.
Abstract An important component of the Alpine vertebrate record of Late Triassic age derives from the Kössen Formation, which crops out extensively in the eastern Alps. Here, we present an isolated and only partially preserved large rib, which carries an osteoderm on a low uncinate process. Osteological comparison indicates that the specimen likely belongs to a small clade of marine reptiles, Saurosphargidae. Members of the clade are restricted to the western (today Europe) and eastern margins of the Tethys (today China) and were so far known only from the Anisian stage of the Middle Triassic. The assignment of the new find to cf. Saurosphargidae, with potential affinities to the genus Largocephalosaurus from the Guanling Formation of Yunnan and Guizhou Provinces, China, would extend the occurrence of the clade about 35 million years into the Late Triassic.
Gustavo A. Ballen, Carlos Jaramillo, Fernando C. P. Dagosta
et al.
Abstract Freshwater fossil fish faunas have been long used to infer past drainage connections, as they are bounded by physical freshwater barriers. Here we study a middle Miocene (15.0-–15.5 Ma) freshwater fish fossil fauna (Makaraipao) from the Castilletes Formation in northern Colombia, nowadays west of the Andes. We record the presence of lungfishes ( Lepidosiren ), pacus ( Mylossoma and Piaractus ), armored catfishes (Callichthyidae), and red-tail catfishes ( Phractocephalus ). Extant members of all those groups (except the Callichthyidae, due to lack of taxonomic resolution) are found in Amazonian faunas east of the Andes and are absent from faunas west of the Andes, indicating that the riverine systems of the Guajira Peninsula were connected to Amazonia during the middle Miocene. The similarity of La Venta (west of the Andes) and Rio Acre (east of the Andes) fish faunas during the late Miocene further indicates that the northern Andean uplift was not a complete barrier at least until ∼ 11 Myr ago. However, there is a continental-wide structuring of the Miocene fish faunas that is also found in the extant faunas, suggesting that other factors such as ecological conditions, in addition to the uplift of the Andes, have shaped the biogeographic evolution of South American fish faunas.
FILIPPO BERTOZZO, BRUNO CAMILO DA SILVA, DAVID MARTILL
et al.
The pterosaur fossil record in Portugal is scarce, comprising mainly isolated teeth and rare postcranial material. Here,
we describe a well-preserved right proximal femur of a pterodactyloid pterosaur from the Kimmeridgian, Upper Jurassic
Praia da Amoreira–Porto Novo Formation of Peniche, Portugal. It is noteworthy for its relatively large size, compared to
other Jurassic pterosaurs. It shows affinities with dsungaripteroids based on a combination of features including the bowing
of the shaft, the mushroom-like cap of the femoral head, and the distinctly elevated greater trochanter. The femur has
a relatively thinner bone wall compared to dsungaripterids, and is more similar to basal dsungaripteroids. A histological
analysis of the bone cortex shows it had reached skeletal maturity. The preserved last growth period indicates fast, uninterrupted
growth continued until the final asymptotic size was reached, a growth pattern which could best be compared
to pterodactyloid femora from the Early Cretaceous. The specimen is the second confirmed report of a dsungaripteroid
from the Jurassic, and it is the first record of this group from the Iberian Peninsula.
Yuri Kimura, Yukimitsu Tomida, Daniela C. Kalthoff
et al.
Fossil rodents are generally scarce in the Miocene of Japan. However, as much as three taxa of eomyid rodents had been reported from the early Miocene Nakamura Formation (ca. 18.5 Ma) in Gifu Prefecture, central Japan. In this study, we revisit one of them—the small-sized taxon—and assign this material to a new genus, Japaneomys, which is so far known only from the type locality. The new genus is closely related to but distinguished from Asianeomys, which is more widely distributed in Central and East Asia, by having: (i) more bunodont cheek teeth with lower lophids, yet complete transverse lophids; (ii) two-rooted p4; (iii) anterior lobe narrower than posterior lobe on m1, correspondingly synclinid I shorter and shallower than synclinid IV; (iv) hypolophid anteriorly concave on m1. Japaneomys shows a derived but peculiar four-layered enamel microstructure with longitudinally oriented Hunter-Schreger bands, compared to three-layered microstructure in typical eomyid rodents. A phylogenetic analysis indicates that Japaneomys is more basal than Asianeomys and likely diverged in the late Oligocene when Japan was still part of the eastern margin of continental Asia, suggesting that certain small mammal populations could have undergone allopatric speciation isolated from inner-continental regions of Asia.
AbstractX-ray computed tomography (CT) provides a nondestructive means of studying the inside and outside of objects. It allows accurate visualization and measurement of internal features, that are otherwise impossible to obtain nondestructively, and is a lasting digital record that can be made available to future researchers, museums, and the general public. Here, an overview of CT scanning methodologies and protocol is provided, as well as some recent examples of how this technology is allowing paleontologists to make new inroads into understanding the ecology, evolution, and development of both extant and extinct organisms. Lastly, some frontiers and outstanding questions in the acquisition, processing, and storage of digital 3-D morphological data are highlighted.
There are remarkably few direct fossil records of Copepoda, which implies that current estimates of the lineage divergence times and inferences on the historical biogeography remain highly dubious for these small-sized crustaceans. The Cyclopidae, a predominantly freshwater copepod family with 1000+ species and distributed worldwide, has no fossil record at all. Recent collections from the middle Miocene Barstow Formation in Southern California resulted in ample material of finely preserved cyclopid fossils, including both adult and larval stages. To document the antennulary setation pattern in the adult and copepodid instars we used a coding system that is coherent between sexes and developmental stages. The majority of the cyclopid fossils, coming from saline lake environment, represent the modern genus Apocyclops, a euryhaline, thermophilic group occurring both in the New World and Old World. A new species Apocyclops californicus is described, based on the short medial spine and spiny ornamentation of the free segment of leg 5, spinule ornamentation of pediger 5, and well-developed protuberances of the intercoxal sclerite of leg 4. The presence of antennal allobasis and the features of the swimming legs unambiguously place the Miocene Apocyclops in the A. panamensis-clade, a predominantly amphi-Pacific group. The middle Miocene fossils with clear affinities to a subgroup of Apocyclops imply an early Miocene or Paleogene origin of the genus. Based on the geographic patterns of the species richness and morphology in Apocyclops and its presumed closest relative, genus Metacyclops, we hypothesize that: (i) the ancestor of Apocyclops, similar in morphology to some cave-dweller Metacyclops occurring today in the peri-Mediterranean region, might have arrived in North America from Europe via the Thulean North Atlantic bridge in the late Paleocene–early Eocene; (ii) Eocene termination of the Thulean land connection might have resulted in the divergence of Apocyclops from the Metacyclops stock.
Resumen. Se analizaron los atributos tafonómicos de una muestra de microvertebrados constituida por 67805 restos esqueléticos del sitio arqueológico Cueva Tixi (Tandilia oriental, provincia de Buenos Aires, Argentina). Se registraron restos asignados a mamíferos, aves, anuros, ofidios y peces, todos con alteraciones, en una secuencia de 11000 años (Pleistoceno Tardío–Holoceno tardío). La mayor proporción de la muestra compuesta por roedores, marsupiales didélfidos, aves, anuros y algunos peces presenta trazas de digestión y proporciones esqueléticas que indican que fue depositada por aves rapaces nocturnas. Se trata de acumulaciones de huesos con alteraciones muy homogéneas en toda la secuencia estratigráfica. En el caso de los restos de ofidios, su depósito se habría producido por muerte en el sitio durante el letargo. Los restos de roedores cávidos del Holoceno tardío final tienen marcas de corte de artefactos y una preservación del esqueleto que demuestran su manipulación antrópica. Las alteraciones posdepositacionales más frecuentes fueron las fracturas. Las marcas de raíces o las adherencias de minerales presentaron tendencias de aumento o disminución de sus frecuencias en la secuencia.
PALABRAS CLAVE. Alteraciones óseas. Egagrópilas. Preservación esquelética.
Abstract. MICROVERTEBRATE TAPHONOMY OF THE ARCHAEOLOGICAL SITE CUEVA TIXI (LATE PLEISTOCENE–LATE HOLOCENE) EASTERN TANDILIA (BUENOS AIRES PROVINCE, ARGENTINA). The taphonomic attributes of a sample of microvertebrates composed by 67805 remains, from the archaeological site Cueva Tixi (Eastern Tandilia, Buenos Aires Province, Argentina), were analyzed. Mammals, birds, frogs, snakes and fish were recorded with natural or anthropogenic modifications in a sequence of 11000 years (Late Pleistocene–late Holocene). The largest proportion of the sample including rodents, didelphid marsupials, birds, frogs and some fish has traces of gastric digestion and skeletal proportions that suggests that it was deposited by nocturnal prey birds. These accumulations of bones have very homogeneous alterations throughout the stratigraphic sequence. The accumulation of snakes would have occurred by circumstantial death on the cave. The skeletal remains of cavid rodents, from the latest Holocene, have cut marks of artifacts and a skeletal preservation which demonstrate its anthropogenic manipulation. The most frequent alterations were post-depositional breakage. Roots marks and mineral deposits presented increasing or decreasing trends in its frequencies in the sequence.
KEY WORDS. Bone modifications. Owl pellets. Skeletal preservation.
Resumen. El estudio de las tortugas extintas en el territorio argentino se inició hace 157 años cuando el naturalista francés Auguste Bravard nominó la primera especie de tortuga. Desde ese entonces hasta la actualidad se incrementó el conocimiento de los Testudinata del territorio argentino en una progresión geométrica, desde las meras nominaciones de especies sin ningún tipo de caracterización, realizadas por los naturalistas y los pioneros de los estudios paleontológicos del siglo XIX, hasta los estudios anatómicos detallados de la actualidad. Arbitrariamente hemos reconocido tres etapas diferentes en el desarrollo de estos estudios. Una etapa inicial que se extendió por más de 100 años y que abarcó entre 1858 y 1965 caracterizada por menciones esporádicas sobre nuevas especies de tortugas fósiles realizadas por naturalistas extranjeros y argentinos, así como por pioneros de la paleontología. Una segunda etapa que abarcó 27 años comprendida entre los años 1966 y 1993 en la que se realizaron mayormente trabajos de síntesis por parte de paleontólogos de vertebrados y paleoherpetólogos argentinos incluyendo, en algunos casos, la participación de especialistas extranjeros. La última etapa, comprendida entre los años 1994 y 2015, está caracterizada por el estudio sistemático de las tortugas extintas con aportes significativos sobre la anatomía, taxonomía y biogeografía de los Testudinata meso–cenozoicos del territorio argentino.
PALABRAS CLAVE. Testudinata. Triásico. Jurásico. Cretácico. Paleógeno. Neógeno. Cuaternario. Argentina.
Abstract. STATE OF KNOWLEDGE OF THE EXTINCT TURTLES OF THE ARGENTINE TERRITORY: A HISTORICAL PERSPECTIVE. The study of extinct turtles in the Argentine territory began 157 ago when the French naturalist Auguste Bravard nominated the first species of turtle. Since then, the knowledge of the Testudinata in the Argentine territory increased in a geometric progression from mere nominations of species without any characterization, made by naturalists and pioneers of the paleontological studies of the nineteenth century, to the recent detailed anatomical studies. Three different stages in the history of the study of turtles in Argentina can be recognized. The initial stage, that lasted more than 100 years, between 1858 and 1965, the studies were carried out by foreign and Argentine naturalists as well as by pioneers of paleontology. The second stage that lasted 27 years, between 1966 and 1993 in which synthesis works have mainly done by vertebrate paleontologists and Argentine paleoherpetologists, in some cases with the participation of foreign experts. The last stage, between 1993 and 2015, is characterized by significant contributions on the anatomy, taxonomy and biogeography of Meso–Cenozoic Testudinata of the Argentine territory.
KEY WORDS. Testudinata. Triassic. Jurassic. Cretaceous. Palaeogene. Neogene. Quaternary. Argentina.