A. D. Muscente

Private Sector

Konservat-Lagerstätten—deposits with exceptionally preserved fossils of articulated multi-element skeletons and soft tissues—offer the most complete snapshots of ancient organisms and communities in the geological record. One classic example, the Posidonia Shale in southwestern Germany, contains a diverse array of fossils preserved during the ∼183...

Data‐driven discovery in geoscience requires an enormous amount of FAIR (findable, accessible, interoperable and reusable) data derived from a multitude of sources. Many geology resources include data based on the geologic time scale, a system of dating that relates layers of rock (strata) to times in Earth history. The terminology of this geologic...

Acritarch biostratigraphic and δ ¹³ C chemostratigraphic data from the Krol A Formation in the Solan area (Lesser Himalaya, northern India) are integrated to aid inter-basinal correlation of early–middle Ediacaran strata. We identified a prominent negative δ ¹³ C excursion (likely equivalent to EN2 in the lower Doushantuo Formation in the Yangtze G...

Fossilized tree resin, or amber, commonly contains fossils of animals, plants and microorganisms. These inclusions have generally been interpreted as hollow moulds or mummified remains coated or filled with carbonaceous material. Here, we provide the first report of calcified and silicified insects in amber from the mid-Cretaceous Kachin (Burmese)...

The fossil record of parasites is limited thus far. A survey of the fossil record shows that some modes of preservation show a higher potential for the preservation of parasitic remains or parasite–host associations than generally recognized. A better understanding of the taphonomy of parasites is critical to better predict their preservation poten...

Konservat-Lagerstätten—deposits with exceptionally preserved fossils—vary in abundance across geographic and stratigraphic space due to paleoenvironmental heterogeneity. While oceanic anoxic events (OAEs) may have promoted preservation of marine lagerstätten, the environmental controls on their taphonomy remain unclear. Here, we provide new data on...

Ecological observations and paleontological data show that communities of organisms recur in space and time. Various observations suggest that communities largely disappear in extinction events and appear during radiations. This hypothesis, however, has not been tested on a large scale due to a lack of methods for analyzing fossil data, identifying...

Reconstructions of ancient sulfur cycling and redox conditions commonly rely on sulfur isotope measurements of sedimentary rocks and minerals. Ediacaran strata (635–541 Ma) record a large range of values in bulk sulfur isotope difference (Δ34S) between carbonate-associated sulfate (δ34SCAS) and sedimentary pyrite (δ34Spy), which has been interprete...

It is rare to find Early Jurassic crustacean material outside of Europe but the discovery of the Ya Ha Tinda Lagerstätte in Alberta, Canada has significantly increased the number of specimens, specifically of the genus Uncina. New articulated specimens of Uncina pacifica and Uncina ollerenshawi preserve the majority of the cephalothorax and pleon,...

The hyperthermal events of the Cenozoic, including the Paleocene-Eocene Thermal Maximum, provide an opportunity to investigate the potential effects of climate warming on marine ecosystems. Here, we examine the shallow benthic marine communities preserved in the late Cretaceous to Eocene strata on the Gulf Coastal Plain (United States). In stark co...

Konservat-Lagerstätten provide the most complete snapshots of ancient organisms and communities in the fossil record. In the Mesozoic, these deposits are rarely found in marine facies outside Oceanic Anoxic Event (OAE) intervals, suggesting that OAEs set the stage for exceptional fossil preservation. Although anoxia does not guarantee survival of n...

Major radiations of microscopic and macroscopic eukaryotes occurred respectively in the early and middle Ediacaran Period. Various hypotheses have been proposed to attribute these evolutionary events to changes in ocean redox conditions. To date, published models of the Ediacaran ocean in South China have largely been focused on the Upper and Middl...

Most sponges have biomineralized spicules. Molecular clocks indicate sponge classes diverged in the Cryogenian, but the oldest spicules are Cambrian in age. Therefore, sponges either evolved spiculogenesis long after their divergences or Precambrian spicules were not amenable to fossilization. The former hypothesis predicts independent origins of s...

Rocks of Ediacaran age (~635–541 Ma) contain the oldest fossils of large, complex organisms and their behaviors. These fossils document developmental and ecological innovations, and suggest that extinctions helped to shape the trajectory of early animal evolution. Conventional methods divide Ediacaran macrofossil localities into taxonomically disti...

A new genus and species of the Elcanidae (Orthoptera, Elcanoidea), Cascadelcana virginiana n. gen. n. sp., is described based on a forewing specimen from the Upper Triassic (Norian) Cow Branch Formation in the Solite Quarry Lagerstätte near the North Carolina-Virginia boundary, USA. It is distinguished from other elcanid species by its RP+MA1 with...

Significance The geologic record provides evidence of repeated diversification events and mass extinctions, which entailed benchmark changes in biodiversity and ecology. For insights into these events, we explore the fossil record of marine animal communities using a network-based approach to quantifying ecological change over time. The major radia...

Mass extinctions documented by the fossil record provide critical benchmarks for assessing changes through time in biodiversity and ecology. Efforts to compare biotic crises of the past and present, however, encounter difficulty because taxonomic and ecological changes are decoupled, and although various metrics exist for describing taxonomic turno...

Carbonates in the Sete Lagoas Formation (São Francisco craton, Brazil) preserve a record of chemical, biological, and oceanographic changes that occurred during the Ediacaran Period. The base of this formation constitutes a post-glacial cap carbonate, which contains seafloor precipitates (carbonate and barite crystal fans) as well as various authig...

In the search for microfossils of early life on Earth, the demonstration of biogenicity is paramount. Traditionally, only syngenetic structures with cellular elaboration, hollow sheaths/cell walls, and indigenous kerogen have been considered bona fide fossils. Recent reports of inorganically preserved microfossils represent a shift from this practi...

The radiation of early animals involved dramatic turnover of both eukaryotic life and marine environments, but the factors that drove origination and extinction of taxa remain controversial. Herein, we review current interpretations and uncertainties regarding changes in biodiversity through the Ediacaran Period. Overall, ocean oxygenation and/or e...

Geologic deposits containing fossils with remains of non-biomineralized tissues (i.e. Konservat-Lagerstätten) provide key insights into ancient organisms and ecosystems. Such deposits are not evenly distributed through geologic time or space, suggesting that global phenomena play a key role in exceptional fossil preservation. Nonetheless, establish...

Exceptionally preserved fossils of non-biomineralized tissues provide key insights into anatomies and communities of ancient organisms. Assemblages of such fossils are not evenly distributed through geologic time or space, suggesting exceptional fossil preservation is controlled by factors operating on global scales. Establishing the influence of g...

Earth's living and non-living components have co-evolved for 4 billion years through numerous positive and negative feedbacks. Earth and life scientists have amassed vast amounts of data in diverse fields related to planetary evolution through deep time-mineralogy and petrology, paleobiology and paleontology, paleotectonics and paleomagnetism, geoc...

Morphology-based phylogenetic analyses support the monophyly of the Scalidophora (Kinorhyncha, Loricifera, Priapulida) and Nematoida (Nematoda, Nematomorpha), together constituting the monophyletic Cycloneuralia that is the sister group of the Panarthropoda. Kinorhynchs are unique among living cycloneuralians in having a segmented body with repeate...

Hydrozoan cnidarians are widespread in modern environments, but their polyps or hydroids, when not biomineralized, are generally rare in the fossil record. To assess the affinities of four hydrozoan taxa previously described on the basis of supposed fossils of non-biomineralized hydroids, we re-analysed the type specimens of these taxa using a comb...

Sphenothallus, a tubular fossil that occurs in Paleozoic strata around the world, may be related to cnidarians or ‘worms,’ but its affinities remain controversial due to preservational variations among localities. Here, to test hypotheses regarding Sphenothallus taphonomy and affinities, we investigate the preservation of new fossils from the lower...

Paleontologists routinely study fossils using high-magnification and high-resolution backscattered electron (BSE) images acquired via scanning electron microscopy (SEM). In BSE imaging, contrast corresponds to differences in backscattering of primary electrons and BSE detection among points in the electron beam raster scan. In general, BSE images a...

Paleontological inferences, molecular clocks, and biomarker fossils indicate sponges evolved in the Cryogenian, but Precambrian sponge fossils are rare, poorly substantiated, and controversial. Spicule-like microstructures (SLMs) hosted in phosphatized fossils from the Ediacaran Doushantuo Formation (∼635–551 Ma) at Weng’an of South China have been...

Fossil preservation through phosphatization and silicification in the Ediacaran Doushantuo Formation (South China): A comparative synthesis,

The rise of multicellularity represents a major evolutionary transition and it occurred independently in multiple eukaryote clades. Although simple multicellular organisms may have evolved in the Mesoproterozoic Era or even earlier, complex multicellular eukaryotes began to diversify only in the Ediacaran Period, just before the Cambrian explosion....

The feather-shaped Plumalina Hall, 1858 is revised on the basis of new and reexamined specimens from New York. Previously described from Givetian through Famennian deposits, a single compression of P. tenera n. sp. from the Rochester Shale extends the range into the Wenlock, and provides new information regarding Plumalina 's biology. We assess the...