Kalaallitkigun jenkinsi
Another haramiyidan revealed, the oldest of them all!
source: https://www.pnas.org/content/early/2020/10/07/2012437117
The earliest-known mammaliaform fossil from Greenland sheds light on origin of mammals
Tomasz Sulej, Grzegorz Krzesiński, Mateusz Tałanda, Andrzej S. Wolniewicz, Błażej Błażejowski, Niels Bonde, Piotr Gutowski, Maksymilian Sienkiewicz, and Grzegorz Niedźwiedzki
Significance
Mammals underwent an adaptive radiation shortly after the acquisition of several morphological characters in their dentition and jaw. Most of these innovations evolved to facilitate more efficient food processing. The double-rooted molariforms with a specialized crown are one such innovation, but their role in the early diversification of mammals has remained poorly understood. This study shows a comprehensive analysis of an early mammaliaform dentary, which combines data from comparative anatomy, CT scanning, and FEA. The new fossil fills an important gap in our understanding of mammaliaform evolution showing a transitional stage between triconodont-like molariform pattern of morganucodontids and multicusped pattern of haramiyidans. Moreover, this study demonstrates that double-rooted teeth are more resistant to bite-related stresses than single-rooted teeth.
Abstract
Synapsids are unique in having developed multirooted teeth and complex occlusions. These innovations evolved in at least two lineages of mammaliamorphs (Tritylodontidae and Mammaliaformes). Triassic fossils demonstrate that close to the origins of mammals, mammaliaform precursors were “experimenting” with tooth structure and function, resulting in novel patterns of occlusion. One of the most surprising examples of such adaptations is present in the haramiyidan clade, which differed from contemporary mammaliaforms in having two rows of cusps on molariform crowns adapted to omnivorous/herbivorous feeding. However, the origin of the multicusped tooth pattern present in haramiyidans has remained enigmatic. Here we describe the earliest-known mandibular fossil of a mammaliaform with double molariform roots and a crown with two rows of cusps from the Late Triassic of Greenland. The crown morphology is intermediate between that of morganucodontans and haramiyidans and suggests the derivation of the multicusped molariforms of haramiyidans from the triconodont molar pattern seen in morganucodontids. Although it is remarkably well documented in the fossil record, the significance of tooth root division in mammaliaforms remains enigmatic. The results of our biomechanical analyses (finite element analysis [FEA]) indicate that teeth with two roots can better withstand stronger mechanical stresses like those resulting from tooth occlusion, than teeth with a single root.
The Gibbons' song
Northern white-cheeked gibbons from Wrocław zoo spend most of their summertime on the island and the tree serves them as a stage. I have shivers every time I listen to their singing.
Actually I love physics very much even if my love isn't reciprocated.
I always had mathematical mind. At school primary and secondary I was best mathematician in my class. But I never really liked math.
Why?
Because it's objects are not real, in the sense that they are idealised and timeless entities which never change. Unlike the real world, I admire, which exists in time and is the product of constant change or maybe even the world IS change.
But the mathematics isn't. Like the idea of Absolute and I am an atheist for a reason. Physics describes that real world’s most basic foundations (from which other sciences subjects emerge representing subsequent higher levels of organisation). It that sense physics is ultimate queen to all other branches of science with mathematics as her handmaiden. And only in this sense is mathematics useful and interesting for me. So I do love physics but my mind isn't that good at it. It just demands very different approach, different kind of thinking than math and of which I'm not capable. But I so do love when people making it share their views with us, poor laymen, showing us amazing mysteries of the very fabric of reality and taking us on mind blowing intellectual journeys through space and time.
I can name but a few of them, those whom I most admire: Lise Meitner, Werner Heisenberg, Paul Dirac, Murray Gell-Mann, Richard Feynman, Hans Bethe, Sheldon Lee Glasgow, Abdus Salam, Leon Lederman, Steven Weinberg, Lee Smolin and Lisa Randall.
The last two are my favourite scientific writers.
RIP Ursula K. Le Guin
― Ursula K. Le Guin, The Farthest Shore
In memory of great writer and larger than life human being. I will miss her wisdom. I will miss her.