iiinova — where your digital self keeps evolving

Andrej Spiridonov @andrejpaleo.bsky.social · 14/10/2026

Article tackles the megabias of the diminishing soft-body preservation in the fossil record: The explanation rests on the proposition, that it was caused by the proliferation of colagen enzyme diversity in bacteria and archaea. www.sciencedirect.com/science/arti... 🧪⚒️ #Geology #Paleobio #EvoBio

Conceptual model for the preservation potential of collagenous soft-bodied animals.

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Andrej Spiridonov @andrejpaleo.bsky.social · 14/10/2026

Whaaat? Flightless bird ("Yuezhuornis yangyuanensis... from southeastern China") in the Jurassic? Dude you literally just learned to fly and you are immediately dropping this superpower. Reminds me the story of limb loss in early tetrapods www.nature.com/articles/s41... 🧪⚒️ #Geology #Paleobio #EvoBio

Phylogenetic position of Y. yangyuanensis and forelimb evolution across the dinosaur–bird transition

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Andrej Spiridonov @andrejpaleo.bsky.social · 12/10/2026

What a wonderful reconstruction. Two alien-looking stem crocodiles enjoying rather unusual prey -- relatives of Archosaurs--turtles. Reminds us that the evolution of crocodiles was dynamic and current forms cover small portion of their diversity. doi.org/10.1017/jpa.... 🧪⚒️ #Geology #Paleobio #EvoBio

Paleoartistic representation of a possible predation event at Tiupampa involving Lapparentemys vilavilensis (based on MHNC-P-18408), a sebecid, and a dyrosaurid. Reconstruction by Miguel Hernandez.

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Andrej Spiridonov @andrejpaleo.bsky.social · 12/10/2026

So, apparently the genetic diversity and the presence of structure is not a remedy for the extinction. At least for endemics on islands. 🧪⚒️ #Geology #Paleobio #EvoBio

From Wikipedia article on Lemerle's Hippopotamus:
Speculative reconstruction of Lemerle's hippopotamus

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Andrej Spiridonov @andrejpaleo.bsky.social · 09/10/2026

Oh a marvelous post about AI solutions to math problems using dinosaur paleontology as a metaphor. blog.ohaithe.re/post/8299720... 🧪

Excerpt from the "Thoughts on AI Solving “Math”"

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Andrej Spiridonov @andrejpaleo.bsky.social · 08/10/2026

Sediments, geochemistry, taphonomy as well as evolutionary patterns usually point to the same transformative events if you know how to read: "The Choteč Limestone-Kačák Member succession represents ... favorable...preservation of microbial microfabrics." link.springer.com/article/10.1... 🧪⚒️ #Geology

Geological and stratigraphic setting of the studied Hlubočepy railroad cut section

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Andrej Spiridonov @andrejpaleo.bsky.social · 08/10/2026

A new study by Andrii Rozhok, Niles Eldredge, and James DeGregori which presents a novel population genetic mechanism of evolution—the directional selection (of deviating forms) also selects, as a dynamic spandrel, higher mutation rate forms! 🧪 #Paleobio #EvoBio doi.org/10.1093/jeb/...

A hypothetical model for how selection regime should impact the evolution of mutation rates

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Andrej Spiridonov @andrejpaleo.bsky.social · 07/10/2026

Which recurrence plot you would prefer: 1) Stroke, 2) Lesion, or 3) Normal? 🧪 #Complexity

Representative SRPs generated by NeuroPrint from co-registered T1/T2/FLAIR MRI slices (Two samples per class, KURDI-MRI).

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Andrej Spiridonov @andrejpaleo.bsky.social · 07/10/2026

'Phylogenetic jungle' of early ecomorphologically diverse actinopretygians: "Early actinopterygians are a paraphyletic assemblage of ~600 extinct species divided between ~22 named clades and the “palaeoniscoids,” a..wastebasket" onlinelibrary.wiley.com/doi/epdf/10.... 🧪⚒️ #Geology #Paleobio #EvoBio

Ecomorphological diversity in early actinopterygians, including body shape and teeth (th)

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Andrej Spiridonov @andrejpaleo.bsky.social · 07/10/2026

As AI systems become more capable in helping in the scientific inference, the challenge becomes the understanding of their inner workings and biases which they can introduce (in arguably different inhuman ways) in the study. www.pnas.org/doi/epdf/10.... 🧪

Comparison of detection performance across five categories of research pitfalls and their overall average. From left to right, panels display accuracy, true positive rate (TPR), false positive rate (FPR), and F1 Score. Error bars represent 95% CI computed via bootstrapping.

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Andrej Spiridonov @andrejpaleo.bsky.social · 04/10/2026

"Vrba'ian" approach in understanding evolution connecting morphology, phylogeny, and the development 👇 "the earliest...evidence of the African buffalo lineage...conserved allometry and heterochrony in the evolutionary history of Syncerus" sciencepress.mnhn.fr/sites/defaul... 🧪⚒️ #Geology #Paleobio

Basal horn core anteroposterior (DAP) and transverse (DT, dorso-ventral in Syncerus Hodgson, 1847) diameters in: A, African fossil and extant bovins

Holotype cranium of Syncerus ekosowan n. sp. OMO 53-10001: A, dorsal; B, ventral; C, anterior; D, posterior; E, left lateral; F, occlusal views. Scale bars: A-E, 10 cm; F, 5 cm.

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Andrej Spiridonov @andrejpaleo.bsky.social · 02/10/2026

'Tug of war' in major bryozoan clades, and the environment-dependence of their dominance: "...lower average temperatures and greater seasonality could give cyclostome bryozoans with relatively slower metabolism an edge in higher latitudes." academic.oup.com/evolinnean/a... 🧪⚒️ #Geology #Paleobio

Proportions of cheilostome species versus latitudes in fossil to Recent assemblages.

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Andrej Spiridonov @andrejpaleo.bsky.social · 02/10/2026

This really cheared my Friday: Paleoartists you are supported even by the pope 👇 #Paleobio

Pope Leo XIV declaration on the nature of arts

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Andrej Spiridonov @andrejpaleo.bsky.social · 01/10/2026

The temporal inertia, legacy and 'memory' causing regional-scale extinction in the Ordovician: "broad accumulations of linguliformean shells and phosphatic hardground clasts...released phosphorous nutrients into the overlying water." www.lyellcollection.org/doi/abs/10.1... 🧪⚒️ #Geology #Paleobio

Obolus Eichwald, 1829
https://fossiilid.info/1268?mode=in_baltoscandia

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Andrej Spiridonov @andrejpaleo.bsky.social · 30/09/2026

Great to see this paper on the importance of higher-order interactions in sustaining organization across scales published! Thank you @svalver.bsky.social for leading the effort in which I've been a small part. The paper: www.sciencedirect.com/science/arti... 🧪 #Complexity #EvoBio #Macroecology

Assembly–persistence space across biological organization.

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Andrej Spiridonov @andrejpaleo.bsky.social · 29/09/2026

Dynamical [chemical] systems view on the emergence of heredity in evolution: "This paper proposes that early chemical systems could preserve and pass on differences through stable chemical states rather than through stored sequences like DNA or RNA" www.pnas.org/doi/10.1073/... 🧪 #Complexity #EvoBio

Behavior of compartments in environments selecting for different autocatalyst composition.

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Andrej Spiridonov @andrejpaleo.bsky.social · 28/09/2026

If we call a modern species poor deeply diverging lineage or "depauperon" (as it is dubbed in the article) the "basal" lineage, then we should admit that the hominids including humans are the "basal" stock for Old World monkey. Right? 😉 academic.oup.com/sysbio/advan... 🧪 #Paleobio #EvoBio

From the Abstract: "Our results highlight the limits of using extant, species-depauperate lineages to infer deep ancestors and the importance of fossils and other evidence that more directly sample early evolutionary history."

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Andrej Spiridonov @andrejpaleo.bsky.social · 26/09/2026

J. Alroy's (johnalroy.bsky.social) article on the unreliability of the coverage-based rarefaction; also known in paleontology as the SQS subsampling, in estimating species richness. Use other techniques folks... nsojournals.onlinelibrary.wiley.com/doi/pdfdirec...

Violin plots (Adler et al. 2025) showing diversity estimates yielded by seven estimators when applied to data simulated under three distributions.

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Andrej Spiridonov @andrejpaleo.bsky.social · 25/09/2026

Interesting article on the geophysical and geodynamic constraints of the Early Earth in the Hadean on the origins and persistence of the RNA organisms: "...frequent global sterilization events persisted up until about 4.4 Ga..." www.nature.com/articles/s41... 🧪⚒️ #Geology #Paleobio #EvoBio

Volume for biocompatible mild temperatures in the range 20–50 °C

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Andrej Spiridonov @andrejpaleo.bsky.social · 25/09/2026

With these tools the identification of anonymous reviewers of papers is pretty easy these days. There are two ways: 1) use soulless AI which would not reveal your style. But it is explicitly banned in most journals due risk of leaking. 2) Reveal yourself and be polite. arxiv.org/pdf/2602.16800 🧪

The first page of the paper on LLM deanonymization

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Andrej Spiridonov @andrejpaleo.bsky.social · 24/09/2026

Looks liek a promissing general approach for the choice of characters (in this application -- the genomic ones). Complexity approach on improving the phylogenetic inference with highlighting highly heterogenous regions of the genome. www.biorxiv.org/content/10.6... 🧪 #EvoBio #Paleobio

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Andrej Spiridonov @andrejpaleo.bsky.social · 24/09/2026

Salt (NaCl) as the helper of thrust-fault tectonic movement: "The overall mechanics of fold-and-thrust belts are significantly different in the presence of salt ...because at typical shaIlow-crustal temperatures salt is exceptionally weak." www.sciencedirect.com/science/arti... 🧪⚒️ #Geology

Estimation of stress versus depth in fold belts

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Andrej Spiridonov @andrejpaleo.bsky.social · 23/09/2026

Just a reminder, that birds had 1.6 times more history before the K-Pg impact than the duration of the Cenozoic Era. My bet would be that we are severely underestimating Mesozoic diversity of birds (stem or crown). www.tandfonline.com/doi/epdf/10.... 🧪⚒️ #Geology #EvoBio #Paleobio

Simplified summary time-scaled tree of the phylogenetic relationships of Mesozoic Avialae. All taxa except Neornithes areextinct; thicker boxes mark the temporal range of each taxon recorded by their fossil record; shaded areas indicate regions ofparticular phylogenetic uncertainty. Fading branches indicate uncertain placement and phylogenetic disconnect between Early andLate Cretaceous taxa. Divergence times largely based on those from M. Wang et al. (2021).

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Andrej Spiridonov @andrejpaleo.bsky.social · 22/09/2026

Gift from kids. Improper CLAMP-like analysis of the leaf shapes suggests the average yearly temperatures of 8 - 12 °C (Real one for Lithuania is 8.3 °C).

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Andrej Spiridonov @andrejpaleo.bsky.social · 22/09/2026

Today I've learned that Douglas Erwin is (classical) palaeontology doomer. Is it that bad in US palaeontology? journals.publishing.umich.edu/ptpbio/artic... 🧪⚒️ #Geology #EvoBio #Paleobio

Concluding remarks from Douglas Erwin article "Quo Vadis Paleontology"

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Andrej Spiridonov @andrejpaleo.bsky.social · 21/09/2026

The macroscale occurences of iron-rich duricrust regoliths in South-Eastern Africa reflects Eon-scale evolution of the megaclimate in this region. With warm and humid periods corresponding to Devonian, Late Cretaceous and Quaternary. www.nature.com/articles/s43... 🧪⚒️ #Geology

The up-to-date model of evolution of theNPthrough the geological times.

Localization, geological characteristics and uplift history of the Nyika
plateau (NP)

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Andrej Spiridonov @andrejpaleo.bsky.social · 20/09/2026

"The Toarcian Oceanic Anoxic Event (T-OAE, ~183 Ma) was a major hyperthermal event...Our simulations indicate the release of ~18,000 Pg C of predominantly magmatic carbon..." The scale is impressive, but I guess there is an order of magnitude uncertainty.. www.nature.com/articles/s41... 🧪⚒️ #Geology

Comparison of published estimates of carbon release during the T-OAE with our cGENIE model results

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Andrej Spiridonov @andrejpaleo.bsky.social · 18/09/2026

The fossil record not only constrains the evolution in the space-time. But it also gives the insights on the physical properties of the world at macro scale. Think about this find of Miocene capybaras in Atacama, which points to recency of the desert. www.nature.com/articles/s41... 🧪⚒️ #Paleobio

Trans-Andean dispersal pathways of late Miocene capybaras.

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Andrej Spiridonov @andrejpaleo.bsky.social · 18/09/2026

"Environmental systems are characterized by complex spatial interactions that cannot be fully described through pairwise relationships or local uncertainty measures." 🧪⚒️ #Complexity #Geology arxiv.org/abs/2609.18439

Environmental field in the area of Gargano.

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Andrej Spiridonov @andrejpaleo.bsky.social · 17/09/2026

The "Principles of Paleontology, 3rd Edition" is absolutely legendary textbook--as its Sta./Raup predecessors. This book helped me to bootstrap myself into paleobiology. It is now 21 years old now. Science of paleontology needs new hard conceptual paleontology textbook 🧪⚒️ #Geology #EvoBio #Paleobio

The book cover of the "Principles of Paleontology"

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Andrej Spiridonov @andrejpaleo.bsky.social · 17/09/2026

"Measurements of three T. rex teeth from the Late Cretaceous Hell Creek Formation yield a temperature of 36.3 ± 2.5°C (1 SE), comparable to modern endotherms." www.science.org/doi/10.1126/... 🧪⚒️ #Geology #Paleobio

Comparison of calculated Δ47 temperatures for T. rex, crocodilians, and bivalves from the HCF along with body temperature ranges of modern birds, mam-mals, and reptiles.

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Andrej Spiridonov @andrejpaleo.bsky.social · 16/09/2026

"We find three macroevolutionary transitions in mammal assemblages... regional Asianmid-Eocene aridification and...global events—the Paleocene-Eocene Thermal Maximum (...warming 56Ma) and the Eocene-Oligocene Transition (prolonged cooling 34Ma)." www.nature.com/articles/s41... 🧪⚒️ #Geology #Paleobio

Sampling-corrected estimates for richness, turnover, and body mass for total Mammalia, spanning the Paleocene, Eocene, and Oligocene Epochs and corresponding Asian Land Mammal Ages (ALMAs).

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Andrej Spiridonov @andrejpaleo.bsky.social · 15/09/2026

The first gift from my son Konstantinas

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Andrej Spiridonov @andrejpaleo.bsky.social · 14/09/2026

In Lithuanian the similarly prominent (and now completely extinct) animal, which served as the source of place names is the Auroch (Bos primigenius) or "Tauras" in Lithuanian. Tauragė, Tauragnas, Tauro kalnas, Taurapilis, Taurupys etc. Also Kaunas has the Auroch in the coat of arms. 🧪 #Paleobio

The coat of arms of Kaunas features a white auroch

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Andrej Spiridonov @andrejpaleo.bsky.social · 14/09/2026

Interesting and openly accessible book on the alternative radiation of intelligent tetrapods and their brains: AKA birds or avian dinosaurs. Apparently there is everything -- the phylogeny as well as scaling. direct.mit.edu/books/oa-mon... 🧪 #EvoBio #Paleobio

Phylogeny of amniotes with the focus on birds

Brain-body mass scaling in birds and reptiles

Neuron density as a function of body mass in birds, mammals and nonavian reptiles

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Andrej Spiridonov @andrejpaleo.bsky.social · 10/09/2026

Interesting analysis. Biologically this could be interpreted as the case of clade selection for extinction resistance without the internal lower-level improvement in survivorship dynamics. Genera live longer because extinction selects for their toughness. www.biorxiv.org/content/10.6... 🧪⚒️ #Paleobio

Event survival curves reveal age dependence punctuated by earlier extinction filters

Allowing toughness to consistently increase or decrease over time does not improve the fit

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Andrej Spiridonov @andrejpaleo.bsky.social · 09/09/2026

Game of GO of killer whales hunting walruses link.springer.com/article/10.1... 🧪

Scheme of cooperative attacks made by killer whales: A1–A34, no. of attack; 1–6, no. of killer whale.

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Andrej Spiridonov @andrejpaleo.bsky.social · 08/09/2026

Maybe anybody can comment of the taxonomic affinity of this fossil cephalopod found by my student? It is an erratic boulder from Lithuania, most probably of Ordovician or Silurian age. 🧪⚒️ #Paleobio

Fossil cephalopod in the erratic boulder

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Andrej Spiridonov @andrejpaleo.bsky.social · 07/09/2026

New genus and species of lungfishes from the Famennian of Latvia - Jumisodus latus, named after the god "Jumis" from old Baltic mythology. 🧪⚒️ #EvoBio #Paleobio

Comparison of selected Paleozoic lungfishes with tooth plates and parasphenoid in palatal view from digital 3D models.

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Andrej Spiridonov @andrejpaleo.bsky.social · 07/09/2026

We all know big-headed giant theropods. But what about big-clawed and strong-arm predatory dinosaur evolution? "..Megaraptoridae...the only large-bodied carnivorous theropod lineage retaining a specialized forelimb-based predatory strategy.." link.springer.com/article/10.1... 🧪⚒️ #EevoBio #Paleobio

(A) Ancestral state reconstruction of log-transformed claw centroid size under a Brownian motion model estimated using REML. (B) Phenogram
of log-transformed claw centroid size through time, illustrating the evolutionary trajectories of Megaraptora (blue), phylogenetic outgroups (light green),
Allosauria (black), Megalosauria (green), and Coelurosauria (red). (C) Fitted values from the phylogenetic generalized least squares (PGLS) model relating
Procrustes-aligned shape data to systematic category and size

Phylogenetic integration patterns (effec t siz e in the left and r-PLS on the right of the black line) and evolutionary rates of claw, ulna-radio, and humerus among non-avian theropod clades with well-developed forelimbs. ( Joaquinraptor skeletal reconstruction modified from Ibiricu et al., 2025 ). Evolutionary rates of hindlimb elements were estimated using the set of Procrustes Coordinates ( compare.evol.rates function, geomorph v. 4.0.9 package) under a Brownian evolution model with 10,000 interactions and a permutational procedure.

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Andrej Spiridonov @andrejpaleo.bsky.social · 07/09/2026

Present is just a point in time, and all the present patterns are a random realization of many processes, which can miss generalities "inclusion of extinct species...revealed a significantly negative relationship between temperature and body mass" onlinelibrary.wiley.com/doi/10.1111/... 🧪⚒️ #Paleobio

Scatterplots showing the relationship between body mass in grams (log10) and mean annual temperature.

Reconstructed Phylogeny of Canidae by Wang et al. (2008) and Zrzavý et al. (2018), annotated with body mass, represented by a bar chart alongside the tree, with mass expressed in grams

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Andrej Spiridonov @andrejpaleo.bsky.social · 04/09/2026

Surprisingly wide range of prey of the extinct "American cheetah": "Yukon population occupying an elevated trophic position consistent with exploitation of anadromous fish, while the Wyoming population functioned as a generalist terrestrial predator." cell.com/current-biol... 🧪⚒️ #Geology #Paleobio

Geographic distribution and sample localities for M. trumani

Miracinonyx catching salmon. Artwork by Hodari Nundu.

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Andrej Spiridonov @andrejpaleo.bsky.social · 04/09/2026

Ordovician-Silurian Baltic Basin keeps in it's layers the record of mega-colossal volcanic eruption events (VEI8 en.wikipedia.org/wiki/Volcani...) in a form of metabentonites. Apparently some of them came from England--many thousands of km away back in the day doi.org/10.1130/B388... 🧪⚒️ #Geology

Paleogeographic reconstructions for Late Ordovician (ca. 454 Ma) and Early Silurian (ca. 440 Ma), after Torsvik and Cocks (2016) and Domeier (2016). Super-eruptions from arc volcanoes in England and backarc volcanoes in Wales and Ireland (Eastern Avalonia) deposited thick tephra of Sandbian age in Baltoscandia. A contribution from an inferred volcanic arc located on juvenile crust of the S North Sea Lüneberg Terrane, now concealed beneath the Mid-North Sea High (Fig. 1), cannot be excluded.

Schematic and conjectural illustration of Wash Igneous Complex (WIC) evolution constrained by thermal ionization mass spectrometry U-Pb zircon ages and igneous apatite microphenocryst chemistry.

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Andrej Spiridonov @andrejpaleo.bsky.social · 04/09/2026

Wonderful world of cephalopod evolution in deep time... " Here we provide an overview of some exciting fields in cephalopod research, where (in our biased opinion) the most impressive advances have been made." 🧪⚒️ #Geology #Paleobio #EvoBio www.cambridge.org/core/journal...

Morphological changes during the evolution from bactritids (top) to the first and slightly derived Devonian ammonoids and changes in ecology.

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Andrej Spiridonov @andrejpaleo.bsky.social · 04/09/2026

This could be called 'hyper-optimization-lead impedance of the exaptive problem exploration'. 🧪 #EvoBio #Complexity

Discussion by Terrence Tao about the importance of the journey in the [mathematical] discovery in developing science and the general understanding.

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Andrej Spiridonov @andrejpaleo.bsky.social · 03/09/2026

Interesting hypothesis of firelight in the campfire as the modulator of the humans speech in the frequency space. Coevolution of biotic-cultural traits with the (local) fabricated environment. royalsocietypublishing.org/rspb/article... 🧪⚒️ #EvoBio #Archeology #PhilSci

Firelight flicker rate quantified through high-speed video capture

The fireside niche is a dynamic light environment and social space.

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Andrej Spiridonov @andrejpaleo.bsky.social · 02/09/2026

#Bretskyan_hierarchy perspective on the Neanderthal dispersal capacities through the glacial-interglacial times. www.nature.com/articles/s43... East-west dispersal zone seems immutable through tens of thousands of years, including historical times. 🧪⚒️ #Geology #Paleobio

Continental-scale dispersal corridors of Neanderthals during the Last Interglacial (MIS5e)

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Andrej Spiridonov @andrejpaleo.bsky.social · 31/08/2026

No Bergmann's rule for megalodon: "regressions yield positive slopes..contradicting... Bergmann’s rule..nursery designation explains a substantially greater proportion of body size variation.." Should we be surprised for a global predator? onlinelibrary.wiley.com/doi/epdf/10.... 🧪⚒️ #Paleobio

Relationship between palaeotemperature and total length of Otodus megalodon across nine fossil assemblages, each repre-sented by a unique palaeotemperature estimate

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Andrej Spiridonov @andrejpaleo.bsky.social · 30/08/2026

Earth is a strange, and extreme place. In September 23, 2023 there was a collapse of 25 million tons of ice in east Greenland fjord. It resulted in a local megatsunami with waves 100-200 m high, which oscillated inside the fjord for 9 days! www.science.org/doi/epdf/10.... 🧪⚒️ #Geology

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