In this article, we document the widespread presence of bony ridges in the neural canals of non-avian dinosaurs, including a wide diversity of sauropods, two theropods, a thyreophoran, and a hadrosaur. These structures are present only in the caudal vertebrae. They are anteroposteriorly elongate, found on the lateral walls of the canal, and vary in size and position both taxonomically and serially. Similar bony projections into the neural canal have been identified in extant teleosts, dipnoans, and urodelans, in which they are recognized as bony spinal cord supports. In most non-mammals, the dura mater that surrounds the spinal cord is fused to the periosteum of the neural canal, and the denticulate ligaments that support the spinal cord can pass through the dura and periosteum to anchor directly to bone. The function of these structures in dinosaurs remains uncertain, but in sauropods they might have stabilized the spinal cord during bilateral movement of the tail and use of the tail as a weapon. Of broader significance, this study emphasizes that important new discoveries at the gross anatomical level can continue to be made in part by closely examining previously overlooked features of known specimens.

BACKGROUND: The fossil record provides the unique opportunity to observe evolution over millions of years, but is known to be incomplete. While incompleteness varies spatially and is hard to estimate for empirical sections, computer simulations of geological processes can be used to examine the effects of the incompleteness in silico. We combine simulations of different modes of evolution (stasis, (un)biased random walks) with deposition of carbonate platforms strata to examine how well the mode of evolution can be recovered from fossil time series, and how test results vary between different positions in the carbonate platform and multiple stratigraphic architectures generated by different sea level curves.
RESULTS: Stratigraphic architecture and position along an onshore-offshore gradient has only a small influence on the mode of evolution recovered by statistical tests. For simulations of random walks, support for the correct mode decreases with time series length. Visual examination of trait evolution in lineages shows that rather than stratigraphic incompleteness, maximum hiatus duration determines how much fossil time series differ from the original evolutionary process. Gradual directional evolution is more susceptible to stratigraphic effects, turning it into punctuated evolution. In contrast, stasis remains unaffected.
CONCLUSIONS: • Fossil time series favor the recognition of both stasis and complex, punctuated modes of evolution. • Not stratigraphic incompleteness, but the presence of rare, prolonged gaps has the largest effect on trait evolution. This suggests that incomplete sections with regular hiatus frequency and durations can potentially preserve evolutionary history without major biases. Understanding external controls on stratigraphic architectures such as sea level fluctuations is crucial for distinguishing between stratigraphic effects and genuine evolutionary process.

The Triassic represents a critical period for understanding the turnover of insect fauna from the Paleozoic to the Mesozoic following the end-Permian mass extinctions (EPME); however, fossil deposits from the Early-Middle Triassic are scarce. The exceptionally preserved 239 million-year-old fossil insect fauna recorded at Monte San Giorgio (Switzerland), including 248 fossils representing 15 major insect clades is presented here. Besides the exceptional features, including their small size and excellent preservation, the fossils have importance in the evolutionary history of the group. The taxonomic and ecological diversity recovered, including both freshwater (dragonflies and caddisflies) and terrestrial taxa (true bugs and wasps), demonstrates that complex environments sustained a paleocommunity dominated by monurans (thought not to have survived the EPME), midges, and beetles. Interestingly, a blattodean-like fossil bearing an external ootheca was also found, important for understanding Paleozoic roachoids to extant cockroaches\' transition and the evolution of maternal brood care. Moreover, the youngest and first complete specimen of †Permithonidae and the oldest sawfly fossils were discovered. Finally, round-shaped bodies, compatible with seminal capsules or lycophyte spores, were found on the abdomens of several midge-like individuals. If these are spores, non-seed-bearing plants could have been the first entomophilous plants rather than gymnosperms, as recently supposed. Altogether, these fossils contribute substantially to understanding insect evolution and Paleozoic-Mesozoic faunal turnover.

Worldwide, silicified woods are found in many geological formations. Significantly, the organic materials of wood are no longer dominant; almost all wood fossils have been mineralized into inorganic silica materials. These unique geological processes must be understood to develop better understanding on organic material fossilization, particularly in the micron scale. Therefore, our aim was to characterize the composition of silicified wood using comprehensive microanalysis. The methods utilized were XRF, ICP-MS, XRD, FTIR, and FE-EPMA. Specimens are from Jasinga, West Java, Indonesia. The results showed that wood silicification was controlled by the infiltration of silica from the host rock into the spaces of the wood structure. In Jasinga, they are controlled by Pliocene tuffaceous sedimentary rocks. The ratio of silica phases revealed a trend in the degree of silicification. Besides silica, the distribution of trace elements also demonstrates the geochemical interaction between the wood fossil and host rock. Wood fossils are affected by the gradual replacement of organic carbon-based materials with silica through silicification. Silica enrichment occurs in the internal of wood, facilitates permineralization and recrystallization. Silica replaces organic material and preserves the wood structures. The microanalytical approach provides comprehensive perspectives on wood petrification, leads to better insights for paleontological studies.

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Artificial intelligence tools are new in taphonomy and are growing fast. They are being used mainly to investigate bone surface marks. In order to investigate this subject, a bibliometric study was made to understand the growing rate of this intersectional field, the future, and gaps in the field until now. From Scopus and Google Scholar metadata, graphs were made to describe the data, and inferential statistics were made by regression with the Ordinary Least Squares method. Exploratory analysis with word clouds, topic modeling, and natural language processing with Latent Dirichlet Allocation as a method were also made using the entire corpus from the papers. From the first register until 2023, we found eight articles in Scopus and 32 in Google Scholar; the majority of the studies and the most cited were from Spain. The studies are growing fast from 2016 to 2018, and the regression shows that growth can be maintained in the coming years. Exploratory analysis shows the most frequent words are marks, models, data, and bone. Topic modeling shows that the studies are highly concentrated on similar problems and the tools to solve them, revealing that there is much more to explore with computational tools in taphonomy and paleontology as well.

Fluid dynamics modeling of an Ediacaran ecosystem illustrates an important positive feedback loop between early multicellular organisms and environmental water flow. Early communities thus helped to chemically shape new environments where oxygen-dependent organisms could thrive.

The predation-driven Mesozoic marine revolution (MMR) is believed to have induced a dramatic change in the bathymetric distribution of many shallow marine invertebrates since the late Mesozoic. For instance, stalked crinoids - isocrinids (Isocrinida) have undergone a striking decline in shallow-sea environments and today they are restricted to deep-sea settings (below 100 m depth). However, the timing and synchronicity of this shift are a matter of debate. A delayed onset of MMR and/or shifts to a retrograde, low-predation community structure during the Paleogene in the Southern Ocean were invoked. In particular, recent data from the Southern Hemisphere suggest that the environmental restriction of isocrinids to the deep-sea settings may have occurred at the end of the Eocene around Antarctica and Australia, and later in the early Miocene in New Zealand. Here, we report the anomalous occurrence of the isocrinids in shallow nearshore marine facies from the middle Miocene of Poland (Northern Hemisphere, Central Paratethys). Thus, globally, this is the youngest record of shallow-sea stalked crinoids. This finding suggests that some relict stalked crinoids may have been able to live in the shallow-water environments by the middle Miocene, and further confirms that the depth restriction of isocrinids to offshore environments was not synchronous on a global scale.

Most described Mesozoic ants belong to stem groups that existed only during the Cretaceous period. Previously, the earliest known crown ants were dated to the Turonian (Late Cretaceous, ca. 94-90 million years ago (Ma)) deposits found in the USA, Kazakhstan, and Botswana. However, the recent discovery of an alate male ant in Kachin amber from the earliest Cenomanian (ca. 99 Ma), representing a new genus and species, Antiquiformica alata, revises the narrative on ant diversification. Antiquiformica can be distinctly differentiated from all known male stem ants by its geniculate antennae with elongated scape, extending far beyond the occipital margin of the head and half the length of the funiculus, as well as its partly reduced forewing venation. Furthermore, the combination of a one-segmented waist with a well-developed node, elongated scape extending beyond the occipital margin, and reduced forewing venation, particularly the completely reduced m-cu and rs-m crossveins and absence of rm and mcu closed cells, firmly places the fossil within the extant subfamily Formicinae. Fourier transform infrared spectroscopy (FTIR) confirmed that the amber containing Antiquiformica alata originated from the Kachin mines in Myanmar. This discovery significantly revises our understanding of the early evolution of Formicinae. The presence of Antiquiformica in Cenomanian amber indicates that the subfamily Formicinae emerged at least by the start of the Late Cretaceous, with crown ants likely originating earlier during the earliest Cretaceous or possibly the Late Jurassic, although paleontological evidence is lacking to support the latter hypothesis.
大多数被描述的中生代蚂蚁属于仅生存在白垩纪的基干类群。目前已知最古老的冠群蚂蚁发现于美国、哈萨克斯坦和博茨瓦纳的土仑阶沉积中（晚白垩纪，约94–90 Ma）。然而，在克钦琥珀中发现的一个森诺曼阶早期的有翅雄蚁新种（约99 Ma）——翼古老蚁（ Antiquiformica alata）改变了对蚂蚁类群分化的认识。古老蚁属（ Antiquiformica）与所有已知的雄性蚂蚁明显不同：触角呈膝状；柄节较长，延伸远超过后头边缘，长度约为鞭小节的一半；前翅翅脉部分减少。此外，古老蚁属（ Antiquiformica）具有一个发育良好的腹结节、延伸超过后头边缘的细长柄节、简化的前翅翅脉，尤其是前翅横脉m-cu和rs-m完全消失、翅室rm和mcu不闭合，这些特征都表明翼古老蚁属于现存的蚁亚科。傅里叶红外光谱（FTIR）结果表明这件琥珀来自缅甸克钦矿区。新化石的发现极大地改变了我们对蚁亚科早期演化的认识。在克钦琥珀（森诺曼阶）中发现的古老蚁属（ Antiquiformica）证实蚁亚科至少在晚白垩的早期就已经出现，而冠群蚂蚁出现时间肯定更早。冠群蚂蚁可能起源于白垩纪早期甚至侏罗纪晚期，尽管这一假设还未得到古生物学证据的支持。.

The drivers of Ediacaran-Cambrian metazoan radiations remain unclear, as does the fidelity of the record. We use a global age framework [580-510 million years (Ma) ago] to estimate changes in marine sedimentary rock volume and area, reconstructed biodiversity (mean genus richness), and sampling intensity, integrated with carbonate carbon isotopes (δ13Ccarb) and global redox data [carbonate Uranium isotopes (δ238Ucarb)]. Sampling intensity correlates with overall mean reconstructed biodiversity >535 Ma ago, while second-order (~10-80 Ma) global transgressive-regressive cycles controlled the distribution of different marine sedimentary rocks. The temporal distribution of the Avalon assemblage is partly controlled by the temporally and spatially limited record of deep-marine siliciclastic rocks. Each successive rise of metazoan morphogroups that define the Avalon, White Sea, and Cambrian assemblages appears to coincide with global shallow marine oxygenation events at δ13Ccarb maxima, which precede major sea level transgressions. While the record of biodiversity is biased, early metazoan radiations and oxygenation events are linked to major sea level cycles.