Independent evidence from rocks, fossils, and genes converge on a cohesive narrative of isthmus formation in the Pliocene. The formation of the Isthmus of Panama stands as one of the greatest natural events of the Cenozoic, driving profound biotic transformations on land and in the oceans. Some recent studies suggest that the Isthmus formed many millions of years earlier than the widely recognized age of approximately 3 million years ago (Ma), a result that if true would revolutionize our understanding of environmental, ecological, and evolutionary change across the Americas. To bring clarity to the question of when the Isthmus of Panama formed, we provide an exhaustive review and reanalysis of geological, paleontological, and molecular records. These independent lines of evidence converge upon a cohesive narrative of gradually emerging land and constricting seaways, with formation of the Isthmus of Panama sensu stricto around 2.8 Ma. The evidence used to support an older isthmus is inconclusive, and we caution against the uncritical acceptance of an isthmus before the Pliocene.
Global warming has become one of the most serious threats to biodiversity. However, the responses of endangered tree species in subtropical regions to climate change and their potential distribution shifts remain elusive. In this study, we selected nine rare and endangered tree species in the subtropical forests of China encompassing both coniferous and broad-leaved groups, and conducted an assessment of their suitable distribution patterns and spatial shifts under current and future climate scenarios (SSP126, SSP370, and SSP585). For this we utilized an optimized MaxEnt model integrating multidimensional environmental variables including climate, soil, and topography. The results show that the model has high predictive accuracy after parameter optimization, with mean AUC values exceeding 0.98 for both broad-leaved and coniferous tree species. Our analysis of environmental factors indicates clear differences in distribution-limiting factors between the two functional groups. Broad-leaved species are primarily constrained by temperature-related variables, particularly the mean temperature of the coldest quarter (Bio11) and the mean diurnal range (Bio2), whereas coniferous species are more sensitive to moisture conditions, with the precipitation of the driest quarter (Bio17) as the key limiting factor for their potential distributions. Under current climatic conditions, highly suitable habitats for both functional groups are mainly concentrated in the middle and lower reaches of the Yangtze River. Under future climate scenarios, broad-leaved species are in general expected to expand in marginal areas, while coniferous species show pronounced scenario dependence, with significant contractions occurring under certain scenarios and time periods. Despite the evident changes at distribution margins, the overall shifts in the centroids of potential distributions for both functional groups will be limited, with core suitable areas remaining relatively stable. This study reveals differences in the spatial response patterns between conifers and broad-leaved trees, and provides a scientific basis for the development of differentiated conservation strategies and the identification of conservation priority areas under climate change.
IGINIO DIENI, Francesco Massari, MARIA ROSE PETRIZZO
et al.
Aimed at integrating knowledge of the Mesozoic succession of eastern Sardinia, two sections of Cenomanian and Santonian ages are presented, and their lithostratigraphical, palaeontological, and biostratigraphical features are described in detail. The former section (Lanaittu, Oliena territory), is composed of upper Cenomanian pelagic limestones unconformably lying on Hauterivian shelf limestones through a fossiliferous conglomeratic hardground of middle Cenomanian age; the latter section (Orosei area), consists of Santonian chalk with basal encrinite that unconformably lies on a conglomeratic hardground of late Albian age, in turn erosively resting on a folded substratum of Lower Cretaceous limestones. The mid-Cretaceous and Santonian unconformities present in both sections and in other Cretaceous successions of Sardinia are significant for reconstructing the palaeotectonic history of the island within the geological evolution of the Tethyan domain. The mid-Cretaceous event is interpreted to be related to the SE-directed subduction of the W Ligurian Ocean, which was triggered by the sinistral motion of Iberia with respect to Europe. The Santonian event is attributed to the change to more orthogonal convergence, accompanied by the onset of forebulge development in Sardinia.
A new maternity colony of lesser horseshoe bats (Rhinolophus hipposideros) was found and described in an abandoned building in Aljezur, Portugal. Between June 25 and July 4, 2022, we conducted emergence and juvenile counts, took light intensity measurements during emergence times and evaluated microclimatic conditions inside the roost, namely temperature and relative humidity. Moreover, we took ultrasound recordings in the open and performed transects to locate foraging areas and commuting corridors. We found the colony amounted to at least 501 individuals (371 adults and 130 juveniles), currently the largest known in Portugal and one of the biggest in Europe. Sixteen matching echolocation calls were recorded away from the colony near a water reservoir, a probable foraging area together with the Vale da Telha valley connecting the roost to the water body, which may also serve as a commuting corridor. Considering the threatened conservation status of the lesser horseshoe bat, the large colony size and its lack of protection, we proposed several conservation measures aimed at preserving the colony. We hope our recommendations will be included in the management plan currently being prepared for the Natura 2000 site Costa Sudoeste. Following up on this research, a radio-tracking study would definitively confirm the bats’ movements and foraging grounds.
New material of the derived baenid turtle Boremys pulchra from the Hell Creek Formation of Montana extends the stratigraphic range of the taxon through at minimum the latest Maastrichtian. Previously, the species was constrained to the Campanian of Montana and Alberta, so this extension constitutes at least 5 million years. Due to fossil reworking at the Bug Creek Anthills assemblage, where Maastrichtian and Paleocene deposits are mixed, a definitive extension for B. pulchra cannot currently include Paleocene strata. However, the presence of B. pulchra in latest Cretaceous strata, previous identification of Paleocene Boremys sp. and the general success of baenid taxa across the K–Pg boundary, make it quite plausible that B. pulchra survived the extinction event and that previously described Maastrichtian and Paleocene Boremys sp. material probably represents a new taxon. A stratigraphic extension beyond the Campanian indicates that B. pulchra survived the paleoenvironmental conditions of the latest Cretaceous, where adaptation to locally heterogeneous aquatic habitats and paleotemperature fluctuations may have facilitated latest Cretaceous and K–Pg survivorship. Additionally, ectoparasitic bore marks on the Boremys pulchra specimen described here can be attributed to the ichnotaxon Karethraichnus lakkos.
PAULA G. PAZINATO, CAROLIN HAUG, ROSEMARIE ROHN
et al.
The process of interpreting and evaluating a fossil is a difficult task. Isopoda is a species rich group of peracarid eumalacostracans which represent quite a challenge when found as fossils, independent of whether we are working with fragmentary or more complete specimens. Here we describe a new fossil species of crustacean, Platuropodus odysseus n. gen. n. sp., from the Irati Formation, Permian of Paraná Basin, Brazil. After misinterpretations, the fossil taxon is recognised here as a representative of Isopoda. The new species presents characters found in Phreatoicidea, Asellota and Oniscidea in a unique combination for the fossil and extant record, such as two pairs of sub-chelate anterior trunk appendages, a short region after the anus and flat uropods. This chimera-like morphology and a morphometric analysis of the sub-chelae indicate convergent evolution in the early diversification of Isopoda. The morphological diversification present in the Palaeozoic and Mesozoic fossil record of Eumalacostraca indicate a “push of the past” effect in different ingroups of Peracarida.
Abstract This study explores body size in sepiids (Cephalopoda, Sepiidae) on the interspecific scale and provides an overview of their geographical distribution. Results reveal a highly skewed distribution of body size variation for raw values and a nearly normal distribution for log-transformed data. However, normality is not statistically validated due to the overrepresentation of small and large species. The geographical distribution of sepiids reveals five main clusters: Atlantic, Cape Basin, Indian Ocean, Asia-Pacific, and Australian. On average, clusters display more or less the same mean body size pattern except the Cape Basin cluster, which is statistically different from the others (smaller interspecific mean body size). The reasons remain unclear but a phylogenetic effect is suspected as southwest African coastal waters concentrate species from the ‘Hemisepius’ complex which is made up of small species. Sepiids do not obey Bergmann’s rule: species from high latitudes do not tend to be larger than species from low latitudes.
The purpose of this operational checklist serves one primary purpose: For an article to 'pass' peer review, articles must satisfy a specific quality threshold based on standardised guidelines. Thus, the quality of the peer review process is simultaneously ensured through an open and technical standardisation process. This should be of interest to all stakeholders engaged in the publishing process, including authors, editors, reviewers, and the publishers themselves, who all have a duty to uphold the integrity of the published research record. While it might initially increase the bureaucracy involved in publishing, ultimately it should save time and effort as it becomes more widely established as an embedded scholarly norm, with integrity a formative part of peer review culture.
Les formations carbonatées de plate—forme de la région occidentale du Massif du Gargano, identifiées à la formation des «Calcaires de San Giovanni Rotondo», appartiennent essentiellement au Crétacé inférieur (Berriasien supérieur p.p. — Aptien inférieur p.p.). Les analogies micropaléontologiques, lithostratigraphiques, biostratigraphiques et faciologiques avec les séries correspondantes des Murges sont remarquables. Comme la région des Murges, le Gargano appartient à la plate—forme apulienne. Ces données permettront d'envisager sous un jour nouveau le fonctionnement géodynamique de la marge garganique durant le Cretace.
Rodrigo T. Müller, Flávio A. Pretto, Micheli Stefanello
et al.
The axial skeleton is proportionally underrepresented in the fossil record of early dinosaurs, when compared to other skeletal parts (e.g., pelvic girdle and hindlimb). For instance, the axis is poorly known in early dinosaurs, which precludes a better understanding of this important anatomical structure. Therefore, the present contribution fills an important gap with a description of the axis of a new early dinosaur (CAPPA/UFSM 0179). The specimen was collected at the Buriol outcrop, a Triassic fossiliferous locality from southern Brazil (Candelária Sequence, Santa Maria Supersequence) biostratigraphically correlated to Carnian units, placing this specimen among the oldest dinosaurs worldwide. Notable features include the combination of a neural spine that bears an almost straight dorsal margin along its length and presence of an epipophysis. This axis arrangement is unique among Carnian dinosaurs, representing a new morphotype, though a similar morphology is observed in some early theropods. Indeed, a phylogenetic analysis nested the specimen within Theropoda. However, this outcome is probably biased by the large amount of missing data in CAPPA/UFSM 0179 and also due to the limited sampling of the axis in early dinosaurs, particularly among sauropodomorphs. As the specimen comes from the site that includes Buriolestes schultzi (an early sauropodomorph), it is quite plausible that CAPPA/UFSM 0179 might be referable to that taxon. If so, the specimen improves the anatomical knowledge of Buriolestes schultzi, given its axis is yet unknown. An alternative possibility to be considered is that the specimen would belong to a dinosaur not yet known in the Candelária Sequence, which would increase its dinosaur diversity for the outcrop, improving the Triassic dinosaurian record from Southern Brazil.
Frederik Spindler, Jocelyn Falconnet, Jörg Fröbisch
This study represents a re-investigation of two historical fossil discoveries, Callibrachion gaudryi (Artinskian of France) and Datheosaurus macrourus (Gzhelian of Poland), that were originally classified as haptodontine-grade sphenacodontians and have been lately treated as nomina dubia. Both taxa are here identified as basal caseasaurs based on their overall proportions as well as dental and osteological characteristics that differentiate them from any other major synapsid subclade. As a result of poor preservation, no distinct autapomorphies can be recognized. However, our detailed investigations of the virtually complete skeletons in the light of recent progress in basal synapsid research allow a novel interpretation of their phylogenetic positions. Datheosaurus might represent an eothyridid or basal caseid. Callibrachion shares some similarities with the more derived North American genus Casea. These new observations on Datheosaurus and Callibrachion provide new insights into the early diversification of caseasaurs, reflecting an evolutionary stage that lacks spatulate teeth and broadened phalanges that are typical for other caseid species. Along with Eocasea, the former ghost lineage to the Late Pennsylvanian origin of Caseasauria is further closed. For the first time, the presence of basal caseasaurs in Europe is documented.
Conchostracans from an outcrop of the Maceió Formation (Aptian-Albian, Alagoas Basin) located at Japaratinga Beach (Alagoas State, Brazil) are studied. The fossils comprise a monospecific fauna of Cyzicus pricei Cardoso, a frequent Early Cretaceous species in some Brazilian rift basins. The conchostracans from Maceió Formation occur as non-articulated and articulated valves of brownish color. The articulated valves and well preserved isolated ones are indicative of local burial without significant transport. No other fossil groups were found associated with Cyzicus pricei in Japaratinga Beach outcrops. Their ecological setting was probably similar to Recent environments: temporary ponds of alkaline freshwater. The existence of some Early Cretaceous African species presenting great morphological similarities with Cyzicus pricei [e.g., Cyzicus kasaiensis (Marlière) from Congo Basin] suggests that Brazil and Africa shared common conchostracofaunas during the Early Cretaceous.
KEY WORDS. Brazil. Alagoas Basin. Cretaceous. Aptian. Conchostracans.
Johnny E. Casas B., Joselys Moreno V., Franklin Yoris V.
The Pampatar Fonnation (Eocene) of Margarita Island, Venezuela, consists mainly of interbedded sandstones and shales, with some conglomerates. These sediments are interpreted as turbidites deposited in submarine canyons and fans. The conglomerates represent canyon and inner-fan-channel deposits. The rest of the succession represents the entire range of fan environments, from inner to outer fan. Triangular diagrams of sandstone composition (100 samples) elucidate the tectonic setting. Most samples plot in the "recycled orogenic" field of the Q-F-L triangle, while the Qm-F-Lt diagram shows a wider dispersion, including "transitional recycled", "mixed zone", and "magmatic arc". This association is interpreted in terms of uplift and erosion of a subduction-accretion complex, which supplied most of the sediments to the Pampatar Formation (recycled orogen component), with an additional, minor contribution from a dissected and transitional magmatic arc.
KEY WORDS. Margarita Island. Pampatar Formation. Eocene. Turbidites. Sedimentary petrography. Triangular diagrams.
New palynological data from the Ferdynandów site are presented and interpreted against the background of the earlier division of this stratotype pollen sequence by Janczyk-Kopikowa (1975), with special attention to a comparison with the nearest profile of a complete Ferdynandovian succession in Łuków (Łuków Plain). The proposed division of the new pollen diagram from Ferdynandów - into two warm periods of interglacial rank separated by a succession typical of glacial periods - is based on the new division of the Ferdynandovian pollen sequence s.l., applied for the first time by Mamakowa (1996) to the Podgórze B1 pollen profile close to Nowe Miasto on the Pilica river. The two warm units and the cold one between them in the new pollen diagram from the Ferdynandów site correspond to the climatostratigraphic units named Ferdynandovian 1 and 2. Together with the cooling/glaciation (Ferdynandovian 1/2) separating them, the whole Ferdynandovian sequence s.l. can be related to the early Middle Pleistocene Cromerian Complex (Cromerian II Westerhoven and Cromerian III Rosmalen) and Marine Isotope Stages (MIS) 13-15.
Virtual paleontology unites a variety of computational techniques and methods for the visualization and analysis of fossils. Due to their great potential and increasing availability, these methods have become immensely popular in the last decade. However, communicating the wealth of digital information and results produced by the various techniques is still exacerbated by traditional methods of publication. Transferring and processing three-dimensional information, such as interactive models or animations, into scientific publications still poses a challenge. Here, we present different methods and applications to communicate digital data in academia, outreach and education. Three-dimensional PDFs, QR codes, anaglyph stereo imaging, and rapid prototyping—methods routinely used in the engineering, entertainment, or medical industries—are outlined and evaluated for their potential in science publishing and public engagement. Although limitations remain, these are simple, mostly cost-effective, and powerful tools to create novel and innovative resources for education, public engagement, or outreach.