Longfeng Li, Dmitry S. Kopylov, Alexandr P. Rasnitsyn
et al.
One new genus and five new species of the extinct family Maimetshidae from mid-Cretaceous Kachin amber are described based on five well-preserved specimens as follows: <i>Maimetshasia nova</i> Li, Kopylov and Rasnitsyn, sp. nov.; <i>Maimetshasia engeli</i> Li, Kopylov and Rasnitsyn, sp. nov.; <i>Guyotemaimetsha perrichoti</i> Li, Kopylov and Rasnitsyn, sp. nov.; <i>Guyotemaimetsha ortegablancoi</i> Li, Kopylov and Rasnitsyn, sp. nov.; and <i>Crucimaimetsha nigra</i> Li, Kopylov and Rasnitsyn, sp. nov. A new generic synonymy is proposed: <i>Turgonalus</i> Rasnitsyn, 1990 (=<i>Turgonaliscus</i> Engel, 2016, syn. nov. and = <i>Ahiromaimetsha</i> Perrichot, Azar, Nel and Engel, 2011, syn. nov.); <i>Guyotemaimetsha</i> Perrichot, Nel and Néraudeau, 2004 (=<i>Burmaimetsha</i> Perrichot, 2013, syn. nov.); <i>Afrapia</i>, Rasnitsyn and Brothers, 2009 (=<i>Afromaimetsha</i>, Rasnitsyn and Brothers, 2009, syn. nov.); and <i>Iberomaimetsha nihtmara</i> Ortega-Blanco, Delclòs and Engel, 2011 are transferred to <i>Afrapia,</i> Rasnitsyn and Brothers, 2009. This results in the following new combinations: <i>Turgonalus cooperi</i>, Rasnitsyn and Jarzembowski, 1998, comb. resurr.; <i>Turgonalus najlae</i> (Perrichot, Azar, Nel & Engel, 2011), comb. nov; <i>Afrapia robusta</i> (Rasnitsyn & Brothers, 2009), comb. nov; and <i>Afrapia nihtmara</i> (Ortega-Blanco, Delclòs & Engel, 2011), comb. nov. The occurrence of various genera of Maimetshidae in amber and compression fossil and the morphological differences of the forewings in all the fossil species are provided, which highlights a high level of genus-level diversity among Mesozoic maimetshids. The key to genera was updated.
The ostracod assemblages from the Upper Permian and Permian-Triassic transitional strata of the Masore section in the External Dinarides (Slovenia) were studied. Altogether 13 genera and 20 species of the orders Palaeocopida, Platycopida and Podocopida are identified and illustrated. All recovered ostracods belong to shallow marine taxa. The older fauna from the uppermost Permian and the younger fauna from the Permian-Triassic boundary strata are distinguished. The obtained fauna from the Permian Bellerophon Formation corresponds to the “benthonic ostracod Eifelian Mega-assemblage” occupying the shelf sea floors. This study presents the first report of ostracod faunas from the uppermost Permian and Permian-Triassic boundary interval of Slovenia. The recovered ostracod fauna display a distinct faunal change and yield important paleobiogeographic implications as it reveals similarity with stratigraphical equivalent faunas from some other neighboring localities in the western Paleotethys, such as Bulla in Italy, Komirić in Serbia, and the Bükk Mountains in Hungary.
Piroska Pazonyi, Zoltán Szentesi, Lukács Mészáros
et al.
The Süttő 21 site is a fissure fill of the freshwater limestone of the Gazda quarry in Süttő. The material was collected between 2017 and 2019, and the results are summarised in this article, with a special focus on the small vertebrate fauna of the site and its stratigraphic and paleoecological significance. The fissure fill can be placed around the Early/Middle Pleistocene boundary (ca. 1.1 and 0.77 Ma). The paleoecological analysis of the herpeto- and mammal fauna of the sequence indicates the proximity of a permanent water body. The lower part of the sequence is dominated by open habitat indicator taxa indicating a cool, dry climate. Towards the upper part of the sequence, the climate remained cool, but became wetter, and the vegetation gradually changed to forest-steppe/open forest. The fauna of the Süttő 21 site can be compared with the material of sites that are of a similar age, thus revealing taxonomic and paleoecological differences between different areas of the country. While a warm, dry climate and open vegetation can be reconstructed in the Villány Hills around the Early/Middle Pleistocene boundary, the Northern Hungarian areas had a cooler, wetter climate and a slightly more closed (sparse forest, forest-steppe) vegetation during this period.
The hindlimbs play a crucial role in bird locomotion, making the biomechanical properties of the musculoskeletal system in these limbs a focal point for researchers studying avian behaviour. However, a comprehensive analysis of the mechanical performance within the long bones of hindlimbs during locomotion remains lacking. In the present study, the strain and deformation of the femur of Cabot's Tragopans (Tragopan caboti) were estimated. We employed inverse simulation to calculate the force and moment of femoral muscles during mid-stance terrestrial locomotion and conducted finite element analysis to calculate femoral strain. Results showed that during mid-stance, the femur experiences combined deformation primarily characterized by torsion, bending, and compression. It emphasises the importance of considering the influence of varying loads on bone adaptation when investigating bone form-function relationships. Muscles were found to play a significant role in offsetting joint loads on the femur, subsequently reducing the deformation and overall strain on the bone. This reduction enhances femoral safety during locomotion, allowing birds to meet mechanical demands while maintaining a lightweight bone structure. Notably, the M. iliotrochantericus caudalis significantly reduces torsional deformation of the proximal femur, protecting the vulnerable femoral neck from high fracture risk induced by rotation load. Given that the femur torsion during terrestrial locomotion in birds is associated with changes in hindlimb posture due to their adaptation to flight, the characteristics of M. iliotrochantericus caudalis may provide insight into the locomotor evolution of theropods and the origin of avian flight.
Floian, Early Ordovician trilobites are systematically described and revised based on new material from the middle part
of the Duoquanshan Formation of the Shihuigou area, northern Qinghai Province, northwest China. The fauna that lived
on the shallow-water carbonate platform comprises three species belonging to two families, i.e., Tsaidamaspis diarmatus,
Zhiyia tsinghaiensis, and Liexiaspis sp. indeterminate. It exhibits a strong endemicity to the Olongbluk terrane. The new
isoteline genus Zhiyia is established on the basis of the material from the Olongbluk terrane and South China palaeoplate,
and is characterized by its: (i) almost obsolete cephalic and pygidial axial furrows; (ii) flattened anterior border
and narrow (sag., exsag.) occipital ring; (iii) bilobed hypostome with a shallow median notch and a small triangular
median projection; (iv) subsemicircular pygidium with wide pygidial axis and border. Faunal evidence indicates that the
palaeogeographic position of the Olongbluk terrane may have been situated closer to the South China palaeoplate rather
than the North China palaeoplate during the Floian.
Rafaella C. Garbin, Saswati Bandyopadhyay, Walter G. Joyce
Neogene (Siwalik-aged) deposits from India and Pakistan have yielded many vertebrate fossils, of which most were named during the 19th century, including numerous geoemydid turtles. In contrast to many other faunal components from the Siwaliks, geoemydids have not undergone taxonomic revision for more than a century and most fossils have therefore been believed to correspond to recent taxa. In this study, we conduct a taxonomic revision of all previously described geoemydid material from the Siwalik-age. We propose that all specimens of ‘Clemmys’ from the Siwaliks of Punjab, Pakistan should be identified as Melanochelys sivalensis comb. nov.; that Melanochelys tricarinata var. sivalensis represents a valid species, for which we propose the replacement name Melanochelys tapani to avoid homonymy; that specimens originally identified as Batagur cautleyi and Pangshura flaviventer cannot be identified beyond the generic level; and that many fragmentary palatochelydians cannot be identified to any particular species or genus due to the lack of preserved diagnostic osteological characters. With a few exceptions, the Siwalik fauna mostly corresponds in its distribution to that of the recent fauna, indicating a certain amount of geographic stasis. However, as the stratigraphic provenance of most material is poor, it is not possible to discern meaningful temporal patterns.
Andy S. Gale, Crispin T.S. Little, Joel E. Johnson
et al.
Valves of a thoracican cirripede belonging to a new species of the Neolepadidae, Ashinkailepas indica Gale sp. nov. are described from a Late Pleistocene cold seep (52.6 ka), cored in the Krishna-Godavari Basin, offshore from the eastern coast of India. This constitutes the first fossil record of the genus, and its first occurrence in the Indian Ocean. Other fossil records of the Neolepadidae (here elevated to full family status) are discussed, and it is concluded that only Stipilepas molerensis from the Eocene of Denmark, is correctly referred to the family. Cladistic analysis of the Neolepadidae supports a basal position for Ashinkailepas, as deduced independently from molecular studies, and the Lower Cretaceous brachylepadid genus Pedupycnolepas is identified as sister taxon to Neolepadidae. Neolepadids are not Mesozoic relics as claimed, preserved in association with the highly specialised environments of cold seeps and hydrothermal vents, but are rather an early Cenozoic offshoot from the clade which also gave rise to the sessile cirripedes.
<p>A new species of stem Orthoptera, namely <i>Phtanomiamia gui</i> gen. et sp.
nov., is described from the Pennsylvanian Xiaheyan locality in China.
Despite the intensive collecting efforts undertaken at this locality, a
single forewing was recovered. It shares with the “lobeattid” <i>Miamia</i> spp. two
peculiar traits, namely a broad ScP–R/RA area and a very early branching
of CuA <span class="inline-formula">+</span> CuPa. On the other hand, it displays a free portion of CuA (between
its divergence from M <span class="inline-formula">+</span> CuA and its fusion with CuPa), a trait allowing
exclusion of the new species from <i>Miamia</i>, to which it is most likely very closely
related.</p>
Nikos Solounias, Nikos Solounias, Melinda Danowitz
et al.
The hypsodont crown of Equus and of other hypsodont ungulates has two functions: It has an extra crown in the alveolus which erupts and becomes a functional crown that enables the horse to live longer and feed on abrasive foods and grit. The second functional aspect is that the crown, while it is in the alveolus, acts as a root to support high stress during mastication. In general, roots do not increase in size during evolution when the tooth crown increases. Delayed development of the true root is a heterochrony phenomenon and is possibly dynamically interactive with the forces applied on the crown. Thus, when the crown becomes worn, as in old age, the mastication forces acting on it are very strong. This is an interesting phenomenon and reinforces our hypothesis of the second functional difference that the young tooth's crown embedded in the alveolus acts as a supporting root. The Equus hypsodont tooth has been represented by a class I lever. That is, the fulcrum is in the middle: the effort is applied on one side of the fulcrum and the resistance (or load) on the other side, for example, as in a crowbar. As an individual Equus ages, the alveolar tooth height decreases. Data display an exponential increase in force generated as tooth height decreases. The elongation and closure of the root is delayed until the crown is almost entirely worn. When the crown becomes worn, the mastication forces acting on it are very strong. This is an interesting phenomenon and reinforces our hypothesis that the young tooth's crown, embedded in the alveolus, acts as a supporting root. This discovery is based on the observation that fossil ungulates most commonly die at an early age, leaving a substantial amount of crown unused. The unused crown is not likely a reserve tooth crown for a season of hardship because it is rare to find examples of such hardships in the fossil record.
Russell D.C. Bicknell, Katie S. Collins, Martin Crundwell
et al.
Summary: The fossil record provides empirical patterns of morphological change through time and is central to the study of the tempo and mode of evolution. Here we apply likelihood-based time-series analyses to the near-continuous fossil record of Neogene planktonic foraminifera and reveal a morphological shift along the Truncorotalia lineage. Based on a geometric morphometric dataset of 1,459 specimens, spanning 5.9–4.5 Ma, we recover a shift in the mode of evolution from a disparate latest Miocene morphospace to a highly constrained early Pliocene morphospace. Our recovered dynamics are consistent with those stipulated by Simpson's quantum evolution and Eldredge-Gould's punctuated equilibria and supports previous suppositions that even within a single lineage, evolutionary dynamics require a multi-parameter model framework to describe. We show that foraminiferal lineages are not necessarily gradual and can experience significant and rapid transitions along their evolutionary trajectories and reaffirm the utility of multivariate datasets for their future research. : Ecology; Biological Sciences; Evolutionary Biology; Phylogenetics; Paleobiology Subject Areas: Ecology, Biological Sciences, Evolutionary Biology, Phylogenetics, Paleobiology
Hirotsugu Mori , Patrick S. Druckenmiller, Gregory M. Erickson
The Liscomb bonebed in the Price Creek Formation of northern Alaska has produced thousands of individual bones of a saurolophine hadrosaurid similar to Edmontosaurus; however, the specific identity of this taxon has been unclear, in part because the vast majority of the remains represent immature individuals. In this study, we address the taxonomic status of the Alaskan material through a comparative and quantitative morphological analysis of juvenile as well several near adult-sized specimens with particular reference to the two known species of Edmontosaurus, as well as a cladistic analysis using two different matrices for Hadrosauroidea. In the comparative morphological analysis, we introduce a quantitative method using bivariate plots to address ontogenetic variation. Our comparative anatomical analysis reveals that the Alaskan saurolophine possesses a unique suite of characters that distinguishes it from Edmontosaurus, including a premaxillary circumnarial ridge that projects posterolaterally without a premaxillary vestibular promontory, a shallow groove lateral to the posterodorsal premaxillary foramen, a relatively narrow jugal process of the postorbital lacking a postorbital pocket, a relatively tall maxilla, a relatively gracile jugal, a more strongly angled posterior margin of the anterior process of the jugal, wide lateral exposure of the quadratojugal, and a short symphyseal process of the dentary. The cladistic analyses consistently recover the Alaskan saurolophine as the sister taxon to Edmontosaurus annectens + Edmontosaurus regalis. This phylogenetic assessment is robust even when accounting for ontogenetically variable characters. Based on these results, we erect a new taxon, Ugrunaaluk kuukpikensis gen. et sp. nov. that contributes to growing evidence for a distinct, early Maastrichtian Arctic dinosaur community that existed at the northernmost extent of Laramidia during the Late Cretaceous.
Soichiro Kawabe, Seiji Matsuda, Naoki Tsunekawa
et al.
Paleontologists have investigated brain morphology of extinct birds with little information on post-hatching changes in avian brain morphology. Without the knowledge of ontogenesis, assessing brain morphology in fossil taxa could lead to misinterpretation of the phylogeny or neurosensory development of extinct species. Hence, it is imperative to determine how avian brain morphology changes during post-hatching growth. In this study, chicken brain shape was compared at various developmental stages using three-dimensional (3D) geometric morphometric analysis and the growth rate of brain regions was evaluated to explore post-hatching morphological changes. Microscopic MRI (μMRI) was used to acquire in vivo data from living and post-mortem chicken brains. The telencephalon rotates caudoventrally during growth. This change in shape leads to a relative caudodorsal rotation of the cerebellum and myelencephalon. In addition, all brain regions elongate rostrocaudally and this leads to a more slender brain shape. The growth rates of each brain region were constant and the slopes from the growth formula were parallel. The dominant pattern of ontogenetic shape change corresponded with interspecific shape changes due to increasing brain size. That is, the interspecific and ontogenetic changes in brain shape due to increased size have similar patterns. Although the shape of the brain and each brain region changed considerably, the volume ratio of each brain region did not change. This suggests that the brain can change its shape after completing functional differentiation of the brain regions. Moreover, these results show that consideration of ontogenetic changes in brain shape is necessary for an accurate assessment of brain morphology in paleontological studies.
The Early Ordovician successions of the southern Montagne Noire consist of a thick sequence of predominantly siliciclastic sediments of which the late Tremadocian St. Chinian Formation and the earliest Floian La Maurerie Formation contain a comparatively rich and abundant cephalopod association. The cephalopods of the St. Chinian and La Maurerie Formation are interpreted as generally authochthonous, representing a fauna which originally lived in the open water above the sediments or related to the sea bottom. The cephalopod associations of the St. Chinian and La Maurerie formations are similar to other contemporaneous assemblages known from higher palaeolatitudes and associated with deeper depositional settings. They are composed almost exclusively of longiconic orthocones, in this case predominantly of eothinoceratids and baltocerids. The occurrences of Annbactrocera, and Bactroceras in the St. Chinian Formation are at present the earliest unambiguous reports of the Orthocerida. The available data suggest an initial expansion of orthoceroid cephalopod faunas from open water habitats of high paleo-latitudes, and a subsequent expansion on the carbonate platforms during the Floian. The presence of the eothinoceratid Saloceras in abundance demonstrates the Gondwanan affinity of the assemblage whilst adding further support for the presence of a "Saloceras realm" that may have extended along the margins of East and West Gondwana at least into intermediate latitudes. The following new taxa are proposed: Annbactroceras n. gen., Annbactroceras felinense n. sp., Cyclostomiceras thorali n. sp., Felinoceras n. gen., Felinoceras constrictum n. sp., Lobendoceras undulatum n. sp., Rioceratidae n. fam., Saloceras murvielense n. sp., Thoraloceras n. gen., Thoraloceras bactroceroides n. sp.doi:10.1002/mmng.201000013
Gabe S Bever, Stephen L Brusatte, Amy M Balanoff
et al.
The internal braincase anatomy of the holotype of Alioramus altai, a relatively small-bodied tyrannosauroid from the Late Cretaceous of Mongolia, was studied using high-resolution computed tomography. A number of derived characters strengthen the diagnosis of this taxon as both a tyrannosauroid and a unique, new species (e.g., endocranial position of the gasserian ganglion, internal ramification of the facial nerve). Also present are features intermediate between the basal theropod and avialan conditions that optimize as the ancestral condition for Coelurosauria--a diverse group of derived theropods that includes modern birds. The expression of several primitive theropod features as derived character states within Tyrannosauroidea establishes previously unrecognized evolutionary complexity and morphological plasticity at the base of Coelurosauria. It also demonstrates the critical role heterochrony may have played in driving patterns of endocranial variability within the group and potentially reveals stages in the evolution of neuroanatomical development that could not be inferred based solely on developmental observations of the major archosaurian crown clades. We discuss the integration of paleontology with variability studies, especially as applied to the nature of morphological transformations along the phylogenetically long branches that tend to separate the crown clades of major vertebrate groups.
The last 5500 years of climate change and environmental response in the northern Benguela Coastal Upwelling are reconstructed by means of three sediment cores from the inner shelf off central Namibia. The study is based on nutrient (δ<sup>15</sup>N, δ<sup>13</sup>C) and productivity proxies (accumulation rates of total organic carbon; AR<sub>TOC</sub>). Reconstructed sea surface temperatures (alkenone-derived SST) and temperatures at subsurface depths (<i>T</i><sub>δ18O</sub>; based on tests of planktonic foraminifers) reflect the physical boundary conditions. The selection of proxy indicators proved a valuable basis for robust palaeo-climatic reconstructions, with the resolution ranging from multi-decadal (NAM1) over centennial (core 178) to millennial scale (core 226620). The northern Benguela experienced pronounced and rapid perturbation during the middle and late Holocene, and apparently, not all are purely local in character. In fact, numerous correlations with records from the adjacent South African subcontinent and the northern hemisphere testify to global climatic teleconnections. The Holocene Hypsithermal, for instance, is just as evident as the Little Ice Age (LIA) and the Roman Warm Period. The marked SST-rise associated with the latter is substantiated by other marine and terrestrial data from the South African realm. The LIA (at least its early stages) manifests itself in intensified winds and upwelling, which accords with increased rainfall receipts above the continental interior. It appears that climate signals are transferred both via the atmosphere and ocean. The combined analysis of SST and <i>T</i><sub>δ18O</sub> proved a useful tool in order to differentiate between both pathways. SSTs are primarily controlled by the intensity of atmospheric circulation features, reflecting changes of upwelling-favourable winds. <i>T</i><sub>δ18O</sub> records the temperature of the source water and often correlates with global ocean conveyor speed due to varying inputs of warm Agulhas Water. It seems as though conveyor slowdown or acceleration not only affected the temperature of the source water but also its nutrient content. This relationship between source water quality and conveyor speed is already known from glacial times.
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doi:<a href="http://dx.doi.org/10.1002/mmng.201100006" target="_blank">10.1002/mmng.201100006</a>