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Andrej Spiridonov @andrejpaleo.bsky.social · 16h

Extinct Pleistocene carnivores were diurnal and had high metabolic rates:
"Only basal metabolic rate and diurnality are robust predictors of extinction, even after accounting for phylogenetic and trait uncertainty"
nsojournals.onlinelibrary.wiley.com/doi/pdfdirec...
🧪 ⚒️ #Paleobio #Macroecology

Results of logistic regression analyses associating traits with extinction outcomes.

Violin plots comparing the basal metabolic rate and threat status of living species.

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Reposted by Andrej Spiridonov

Royal Society Publishing @royalsocietypublishing.org · 6d

New in #PhilTransB - a theme issue exploring one of science’s deepest questions: how life can emerge from non-living matter. Edited by @ricardsole.bsky.social and colleagues. Read: buff.ly/7iz4tGu

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Andrej Spiridonov @andrejpaleo.bsky.social · 2d

Interesting: "Warming altered abundance scaling with size depending on richness; in high-richness communities, temperature favored small protists, steepening the CCSR slope"

On Ka scales there were systemic shifts in size-abundance distribution during extinction event
www.geology.cz/bulletin/ful...

Histograms of the cyst diameters of Leiosphaeridia spp. in the mid-to-upper Homerian from the Viduklë-61 well. The histograms show the raw morphometric data on the taxon from the studied interval shown by graptolite zones. The graptolite zones are based on Radzevičius et al. (2014b).

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Andrej Spiridonov @andrejpaleo.bsky.social · 2d

Human cities are essentially integrated human (almost)super-organismal colonies. Therefore, urbanistics, among other things, studies the astogeny of humans (as integrated functional spatial collectives) at larger — geographical — scales.
arxiv.org/abs/2510.03045
🧪 #Complexity #Geography

Morphologies obtained from Batty et al's model

Simulated urban growth patterns constrained by different transport networks.

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Andrej Spiridonov @andrejpaleo.bsky.social · 3d

Interesting study analyzing paleobiogeographical patterns of the P-Tr extinction and recovery
"ammonoid biogeography was primarily dispersal-constrained during the Griesbachian and Spathian, and niche-constrained during the Smithian"
www.scup.com/doi/full/10....
🧪 ⚒️ #Paleobio #EvoBio #Macroecology

Palaeo-location of the 27 regions of A) conodont and B) ammonoid taxa

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Andrej Spiridonov @andrejpaleo.bsky.social · 5d

The major update on the origins of a major group of fishes based on new fossils:
"Notably, ancestral range and habitat reconstructions indicate marine origins for the otophysan crown groups, with at least two transitions to freshwater"
www.science.org/doi/epdf/10....
🧪 ⚒️ #Paleobio #EvoBio #Geology

Maximum a posteriori tree of otophysans resulting from a Bayesian phylogenetic analysis mapped with ancestral geographic range and habitat environment reconstruction.

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Andrej Spiridonov @andrejpaleo.bsky.social · 6d

Impressive coverage of the ghost-range in leech tree, between the relatives which are found in 200 million year younger (Mesozoic) rocks. I would guess, as many major animal innovations, the true divergence should have been in the mid- Ordovician.
peerj.com/articles/199...
🧪 ⚒️ #Paleobio #EvoBio

Phylogenetic analyses recover Macromyzon as a stem leech

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Andrej Spiridonov @andrejpaleo.bsky.social · 7d

Interesting review article concentrating on some proximal causes of mass extinctions, namely the environmental toxicity of heavy metals.

www.nature.com/articles/s43...
🧪 ⚒️ #Paleobio #EvoBio #Geology

Proposed cause-and-effect relationships of bolide impacts , LIPs, and anthropogenic activity with heavy metal toxicity

Differences in the physiological effects between bioessential and non
bioessential heavy metals in terrestrial sporomorphs and benthic foraminifera

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Andrej Spiridonov @andrejpaleo.bsky.social · 7d

Congratulations Peter with this great synthesis! I've liked the concept of the "Earth System Engineers" -- this whole discussion on the ecosystem engineering was rather restricted in scale, and now it seems, more appropriate concepts and their connections are put forward.

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Andrej Spiridonov @andrejpaleo.bsky.social · 7d

To elaborate the point, I believe there should be a 'spectrum of individuality" of species across the tree of life.

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Andrej Spiridonov @andrejpaleo.bsky.social · 7d

Yes sure, as well as diffusion of molecules with external environment makes us (as organisms) 'approximate' -- fuzzy individuals.

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Andrej Spiridonov @andrejpaleo.bsky.social · 7d

Anagenesis presumes that the splitting is superfluous for the pronounced change. And the overwhelming evidence suggests that the cladogenesis is the main cause of change in all kinds of evolutionary systems (including species).

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Andrej Spiridonov @andrejpaleo.bsky.social · 7d

Study is exploring what paleontologists and neontologists know about the punctuated equilibria, and how they perceive the dominant modes of evolution. As expected, there is a significant variance in views on evolution reflecting differing backgrounds.
doi.org/10.1017/pab....
🧪 ⚒️ #Paleobio #EvoBio

Opinions of evolutionists on the prevalence of different modes of evolution.

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Andrej Spiridonov @andrejpaleo.bsky.social · 7d

One more conceptual layer of the Bretskyan hierarchy: how organisms map on their range and environments or what is the geometry of their movement (as exemplified by dogs and cats).
🧪 ⚒️ #Paleobio #EvoBio #Macroecology
www.pnas.org/doi/epdf/10....

Ridge densities for canids and felids for the nine landscapes in which at least one species from each clade was tracked together.

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Andrej Spiridonov @andrejpaleo.bsky.social · 8d

Earth's strata — the result, the record and the cause of geodynamics, climate changes, and biodiversity structures on our planet.
🧪 ⚒️ #Geology

Zoltán Sylvester @zzsylvester.bsky.social · 9d

Last week I was co-leading a field trip in Utah, to check out some fluvial and eolian rocks. It was exhausting but fun and forced me to think more carefully than before about complex bedforms. This is a 3D model of one of the many stunning exposures of the Navajo Sandstone near Escalante 🧪⚒️

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Andrej Spiridonov @andrejpaleo.bsky.social · 9d

Study tested Sheldon's model of change (in stable environments) and stasis (in unstable): "Plus ça change", while confirming it in phenotypic evolution of bivalves in stable Cretaceous, semi-stable Neogene and unstable Quaternary.
🧪 ⚒️ #Paleobio #EvoBio #Geology
doi.org/10.1017/pab....

Ridgeline plot showing changes in log centroid sizes for Nucula during the Late Cretaceous and Neogene–Quaternary.

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Andrej Spiridonov @andrejpaleo.bsky.social · 11d

A classic of wide-range-of-time scales biogeodynamics just dropped:
www.cell.com/trends/ecolo...
"By integrating modern and deep-time engineering processes, we offer a framework to assess whether human EE activities (and consequences) have parallels in Earth history"
🧪 ⚒️ #Paleobio #EvoBio #Geology

A compilation of engineers – and engineering processes – recognized in humans (top panels), non human organisms (middle), and in the geological record (bottom panels), and arranged on a spectrum of ecosystem engineering (‘EE’) to Earth system engineering (‘ESE’) processes/consequences.

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Andrej Spiridonov @andrejpaleo.bsky.social · 12d

Interesting article revealing hidden layers of the geological instability in the carbon cycle (by extension--climate):
"sedimentary organic carbon burial, amplified by redox-sensitive phosphorus regeneration, can outweigh silicate weathering".
www.science.org/doi/epdf/10....
🧪 ⚒️ #Paleobio #Geology

Time-evolution of the model system in response to perturbation

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Andrej Spiridonov @andrejpaleo.bsky.social · 12d

"differences in squamate fossil record completeness stem from ...anatomy/body size and affinities of different ...groups to specific lithologies and depositional environments."
doi.org/10.1017/pab....
🧪 ⚒️ #Paleobio #EvoBio
Toxiferans: snakes and mosasaurs the kings of the squamate fossil record 👇

Squamate species abundance through time. Occurrences and abundances of major squamate lineages, mapped onto the time-calibrated combined-evidence hypothesis of squamate relationships from Simões et al. (2018).

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Andrej Spiridonov @andrejpaleo.bsky.social · 16d

Today is the 150th birthday of the greatest Lithuanian artist - Mikalojus Konstantinas Čiurlionis. J. R. R. Tolkien was a world builder with words. Čiurlionis was his match in the paintings.
You can look here and imagine a giant azhdarchid flying above the Decan traps before the K-Pg.

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Andrej Spiridonov @andrejpaleo.bsky.social · 16d

Yup, natural selection of the landscape for the durability 🙂

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Andrej Spiridonov @andrejpaleo.bsky.social · 16d

Interesting. To be extinct as a language is a different thing as to be extinct as a species -- in the case of the former, it is much more gradational. Some languages which are deemed to be extinct, have preserved scripts and known grammar, but no living native speakers.
CC: @svalver.bsky.social

Natalia Jagielska @nataliajagielska.bsky.social · 17d

Did you know, that the language diversity is treated the same way one would treat species:

UNESCO Atlas of the World's
Languages in Danger categories

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Andrej Spiridonov @andrejpaleo.bsky.social · 17d

Cool study showing how the physical forcing of the background geochemistry of oceans, drives multiple convergences in the mineralogy of bryozoans!
🧪 ⚒️ #Paleobio #EvoBio

James Saulsbury @jgsaulsbury.bsky.social · Aug 25

New paper out in Geology! Cheilostome bryozoans evolved aragonite skeletons dozens of times during the transition from calcite to aragonite seas, in contrast to other marine calcifiers. Fossil occurrence data corroborate the story and help nail down the timeline. doi.org/10.1130/G537...

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Reposted by Andrej Spiridonov

Peter Wagner (a Real Dr., not a surgeon-barber/body-tech/golfer) @peterjwagner3.bsky.social · Sep 7

If you know anyone interested in starting a Master's project working on ammonoid phylogenetics (or the phylogenetics of a mollusc group spanning the OAE2 event in the Late Cretaceous), then ask them to get in touch with me.

The situation is a little tricky, as it would be funded by the remainder…

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Reposted by Andrej Spiridonov

Matt Friedman @friedmanlab.bsky.social · 26d

Do you like cichlids? Fossils? Fossil cichlids? Would you like to study them as part of a graduate degree at the University of Michigan, joining an NSF-funded project? Get in touch.

Multicolored CT model of a fossil cichlid skeleton. Image credit: Austin Babut (project technician).

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