Ben Creisler
Some recent non-dino papers:
Yu Qiao, Masaya Iijima & Jun Liu (2020)
The largest hupehsuchian (Reptilia, Ichthyosauromorpha) from the Lower Triassic of South China indicates early establishment of high predation pressure after the Permo-Triassic mass extinction.
Journal of Vertebrate Paleontology Article: e1719122
doi:
https://doi.org/10.1080/02724634.2019.1719122 https://www.tandfonline.com/doi/full/10.1080/02724634.2019.1719122[No abstract but from the text:]
We report a partial trunk region of a huge hupehsuchian from the Early Triassic of Hupeh Province, China. The current material represents the largest hupehsuchian ever known, providing further evidence of the early establishment of high predation pressure in the sea before the Middle Triassic.
...
...[T]he body size of the new material (2.29 m)....is not comparable to any known hupehsuchians, being much larger than the largest known species, P. longus (~1.35 m)... However, given the fragmentary nature of the specimen, we here avoid naming a new species.
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Natalia Artemieva & ÂJoanna Morgan (2020)
Global KâPg Layer Deposited From a Dust Cloud.
Geophysical Research Letters 47(6): e2019GL086562
doi:
https://doi.org/10.1029/2019GL086562https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL086562 ?af=R
Although it is widely agreed that the distal KâPg clay layer contains ejecta from the Chicxulub impact site, no current models can explain how these ejecta travel from the impact site around the globe. A widely accepted hypothesis is that impact spherules and shocked minerals in the layer were ejected from an expanding impact plume and traveled to their final destination on a ballistic path. Shocked minerals, however, are ejected at too low a velocity to reach distal sites, and plausible ballistic ejection models cannot explain the observed ejecta distribution. Using a suite of numerical simulations, we find that intense interactions between the ejecta curtain and atmosphere generate a fastâmoving dust cloud traveling at speeds of a few kilometers per second, which carries a substantial fraction of ejecta, including shocked minerals, to distal sites. We conclude that ejecta curtain material must make a major contribution to the formation of the distal KâPg layer.
Plain Language Summary
We first discovered that the Earth had been hit by a large asteroid 66 million years ago when a thin clay layer was found to have an extraterrestrial chemistry. This layer is unique in the geological recordâit can be found all around the world and contains material that originated from the asteroid and Chicxulub impact site. To date, no models have been able to adequately explain how these impact ejecta traveled all around the world. In this paper we show that intense interactions between the highâvelocity ejecta and atmosphere produce a fastâmoving dust cloud, which is able to transport these ejecta much further than previously thought.
Key Points
We use a hydrocode to model interactions between the atmosphere and ejecta curtain material as it leaves the Chicxulub impact site
In all our simulations, intense ejectaâatmosphere interactions lead to the formation of a fastâmoving dust cloud
Ejecta deposited in the distal KâPg clay layer are predominantly transported to their final destination within this dust cloud
News:
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Also may be of interest:
The causes of the reversed sexual size dimorphism (RSD; females larger than males) in birds of prey are subject to a centuries-old, passionate debate. A crucial difficulty is to distinguish whether the postulated benefits derive from the proposed causal process(es) or are incidental. After reviewing the existing literature, we present a methodology that overcomes this difficulty and renders unnecessary any speculative a priori distinctions between evolved function and incidental effects. We can thus justify the following novel version of the well-known nest defence hypothesis as the most likely to explain the phenomenon in all birds of prey that show RSD: if the female predominates in actively defending the eggs and young against predators, then she is the heavier sex, and her relatively greater body mass is adaptive. That is, heavier females are favoured (independently of males) by natural selection. The attractiveness of this hypothesis is that it has the potential to explain the phenomenon in all raptors exhibiting RSD, can deal with the exceptional cases in this group, explains the direction of the dimorphism, focuses on a key factor in the reproductive success of most raptors, is parsimonious, i.e. does not require supporting hypotheses, and is supported by a substantial body of evidence.