Two echinoid species from the Sarcheshmeh Formation, early Aptian, Lower Cretaceous, of the Kopet-Dagh Basin, NE Iran, are described: a phymosomatoid specimen of Tetragramma sp., and the spatangoid echinoid Miotoxaster collegnii (Sismonda, 1844). This is the first report of echinoids from the Sarcheshmeh Formation from northeastern Iran.
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http://dx.doi.org/10.11646/zootaxa.4656.1.5 | DOI Listing |
PeerJ
January 2025
Florida Museum of Natural History, University of Florida, Gainesville, FL, United States of America.
The mechanisms that regulate minor and trace element biomineralization in the echinoid skeleton can be primarily controlled biologically (, by the organism and its vital effects) or by extrinsic environmental factors. Assessing the relative role of those controls is essential for understanding echinoid biomineralization, taphonomy, diagenesis, and their potential as geochemical archives. In this study, we (1) contrast geochemical signatures of specimens collected across multiple taxa and environmental settings to assess the effects of environmental and physiological factors on skeletal biomineralogy; and (2) analyze the nanomechanical properties of the echinoid skeleton to assess potential linkages between magnesium/calcium (Mg/Ca) ratios and skeletal nanohardness.
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December 2024
Department of Molecular Biology, Cellular Biology, Biochemistry, Brown University, Providence, United States.
The evolutionary introduction of asymmetric cell division (ACD) into the developmental program facilitates the formation of a new cell type, contributing to developmental diversity and, eventually, species diversification. The micromere of the sea urchin embryo may serve as one of those examples: an ACD at the 16-cell stage forms micromeres unique to echinoids among echinoderms. We previously reported that a polarity factor, activator of G-protein signaling (AGS), plays a crucial role in micromere formation.
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November 2024
Department of Molecular and Cellular Biology, Brown University, Providence, RI, 02912, USA.
Sea urchins (echinoids) are common model organisms for research in developmental biology and for their unusual transition from a bilaterally organized larva into a post-metamorphic adult with pentaradial body symmetry. The adult also has a calcareous endoskeleton with a multimetameric pattern of continuously added elements, among them the namesake of this phylum, spines. Nearly all echinoids have both large primary spines, and an associated set of smaller secondary spines.
View Article and Find Full Text PDFMar Environ Res
November 2024
Department of Marine Biology and Oceanography, Institute of Marine Sciences (ICM-CSIC), Passeig Maritim de la Barceloneta 37-49, Barcelona, 08003, Catalonia, Spain. Electronic address:
Ocean warming and acidification driven by anthropogenic CO emissions may impact the mineral composition of marine calcifiers. Species with high skeletal Mg content could be more susceptible in polar regions due to the increased solubility of CO at lower temperatures. We aimed to assess the environmental influence on skeletal Mg content of Antarctic echinoderms belonging to Asteroidea, Ophiuroidea, Echinoidea and Holothuroidea classes, along a latitudinal gradient from the South Shetland Islands to Rothera (Adelaide Island).
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September 2024
Geosciences Barcelona (GEO3BCN-CSIC), Solé i Sabarís s/n, 08028, Barcelona, Spain.
Understanding deep-time marine biodiversity change under the combined effects of climate and connectivity changes is fundamental for predicting the impacts of modern climate change in semi-enclosed seas. We quantify the Late Miocene-Early Pliocene [11.63 to 3.
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