Mesozoic and Early Cenozoic marine animals across multiple phyla record secular trends in morphology, environmental distribution, and inferred behaviour that are parsimoniously explained in terms of increased selection pressure from durophagous predators. Another systemic change in Mesozoic marine ecosystems, less widely appreciated than the first, may help to explain the observed animal record...

Marsupial mammal relatives (stem metatherians) from the Mesozoic Era (252-66 million years ago) are mostly known from isolated teeth and fragmentary jaws. Here we report on the first near-complete skull remains of a North American Late Cretaceous metatherian, the stagodontid Didelphodon vorax. Our phylogenetic analysis indicates that marsupials or their closest relatives evolved in North Americ...

Sillimanite is a very important raw material for the manufacture of refractory bricks used in iron and steel, cement and glass industries. In some coastal stretches of south India, the beach sand is contaminated with shell. After recovering heavy minerals like ilmenite, rutile, zircon and garnet by various physical separation techniques, the final sand containing sillimanite, quartz and shell i...

Angiosperms evolved rapidly in the late Mesozoic. Data from the genetic-based approach called ’molecular clock’ permit an evaluation of the radiation of flowering plants through geological time and of the possible influences of Mesozoic mass extinctions. A total of 261 divergence ages of angiosperm families are considered. The radiation of flowering plants peaked in the Albian, early Campanian,...

A new species of abertellid sand dollar, Abertella miskellyi n. sp., is described from the Miocene Camarones Formation of Patagonia, southern Argentina. The new taxon corroborates the existence of the genus in South America, given that Abertella is most common in the southeastern USA and the eastern coast of Central America. It is characterized by a unique basicoronal circle, in which the inter...

The monitoring of urban land surface subsidence is the main task disaster prevention and mitigation. In this paper, process in Changchun metropolitan area calculated based on PS-InSAR technology by using SLC data Sentinel-1B with 50 scenes within from 2016 to 2020. results show that basically a stable state, settlement located southeast around Century Square, maximum rate 20.45mm/a, average 2.9...

The apatite fission track (FT) analysis of Jurassic sandstones from the Beipiao basin in the eastern China indicates a large variation in FT age peaks. The sandstone of the Beipiao Formation has two peak ages at 178.8 and 40.0 Ma, while the sandstone of the Tuchengzi Formation has three age peaks at 152.0, 77.5 and 32.5 Ma. This implies that the provenance of the Beipiao basin in the early Jura...

Organisms with external fertilization are often sperm limited, and in echinoids, larger eggs have a higher probability of fertilization than smaller eggs. This difference is thought to be a result of the more frequent sperm-egg collisions experienced by larger targets. Here we report how two components of egg target size, the egg cell and jelly coat, contributed to fertilization success in a se...

Complex life cycles have evolved independently numerous times in marine animals as well as in disparate algae. Such life histories typically involve a dispersive immature stage followed by settlement and metamorphosis to an adult stage on the sea floor. One commonality among animals exhibiting transitions of this type is that their larvae pass through a 'precompetent' period in which they do no...