Andrej Spiridonov
@andrejpaleo.bsky.social
Professor of paleontology and Earth systems at Vilnius University. My interests are: theoretical paleontology, evolution, geology, stratigraphy, philosophy of biology and geology, climate at scales great and small.
https://twitter.com/AndrejSpiridon4
https://twitter.com/AndrejSpiridon4
"72% of past continental areas across the Cenozoic lack accessible sedimentary rocks..remaining 28%..disproportionately derived from regions that experienced tropical, temperate, and arid climates..cold and polar climates are underrepresented."
doi.org/10.1016/j.pa...
🧪 ⚒️ #Geology #EvoBio #Paleobio
doi.org/10.1016/j.pa...
🧪 ⚒️ #Geology #EvoBio #Paleobio
November 21, 2025 at 2:13 PM
"72% of past continental areas across the Cenozoic lack accessible sedimentary rocks..remaining 28%..disproportionately derived from regions that experienced tropical, temperate, and arid climates..cold and polar climates are underrepresented."
doi.org/10.1016/j.pa...
🧪 ⚒️ #Geology #EvoBio #Paleobio
doi.org/10.1016/j.pa...
🧪 ⚒️ #Geology #EvoBio #Paleobio
"The three great evolutionary faunas" of topic development in the "Systematic Biology" journal? 😃
Seems like decadal-scale topic displacement trends.
academic.oup.com/sysbio/advan...
🧪 #EvoBio #Paleobio #philsci
Seems like decadal-scale topic displacement trends.
academic.oup.com/sysbio/advan...
🧪 #EvoBio #Paleobio #philsci
November 20, 2025 at 8:18 AM
"The three great evolutionary faunas" of topic development in the "Systematic Biology" journal? 😃
Seems like decadal-scale topic displacement trends.
academic.oup.com/sysbio/advan...
🧪 #EvoBio #Paleobio #philsci
Seems like decadal-scale topic displacement trends.
academic.oup.com/sysbio/advan...
🧪 #EvoBio #Paleobio #philsci
Interesting meta-scientific take on the development of theories, as exemplified by the case of paleontology in the Modern Synthesis and the specific Late Turkana mollusk study of the punctuated equilibria.
link.springer.com/article/10.1...
🧪 ⚒️ #EvoBio #Paleobio #philsci
link.springer.com/article/10.1...
🧪 ⚒️ #EvoBio #Paleobio #philsci
November 18, 2025 at 3:52 PM
Interesting meta-scientific take on the development of theories, as exemplified by the case of paleontology in the Modern Synthesis and the specific Late Turkana mollusk study of the punctuated equilibria.
link.springer.com/article/10.1...
🧪 ⚒️ #EvoBio #Paleobio #philsci
link.springer.com/article/10.1...
🧪 ⚒️ #EvoBio #Paleobio #philsci
Although, the author misrepresents our proposed Bretskyan hierarchy (BH) claiming that it lacks reticulate causation.
The BH is explicitly reticulate in diachronic view when different geobiomes can not only diverge but also merge together.
doi.org/10.1017/pab....
2/2
🧪 ⚒️ #EvoBio #Paleobio
The BH is explicitly reticulate in diachronic view when different geobiomes can not only diverge but also merge together.
doi.org/10.1017/pab....
2/2
🧪 ⚒️ #EvoBio #Paleobio
November 18, 2025 at 11:45 AM
Although, the author misrepresents our proposed Bretskyan hierarchy (BH) claiming that it lacks reticulate causation.
The BH is explicitly reticulate in diachronic view when different geobiomes can not only diverge but also merge together.
doi.org/10.1017/pab....
2/2
🧪 ⚒️ #EvoBio #Paleobio
The BH is explicitly reticulate in diachronic view when different geobiomes can not only diverge but also merge together.
doi.org/10.1017/pab....
2/2
🧪 ⚒️ #EvoBio #Paleobio
Interesting article on the role of reticulation in evolution:
"...review tries to draw attention to evolutionary processes that lead to the origin and growth of diversity and complexity in biological systems by reticulations...‘Biology’s Second Law’"
www.mdpi.com/2079-7737/14...
🧪 #EvoBio
1/2
"...review tries to draw attention to evolutionary processes that lead to the origin and growth of diversity and complexity in biological systems by reticulations...‘Biology’s Second Law’"
www.mdpi.com/2079-7737/14...
🧪 #EvoBio
1/2
November 18, 2025 at 11:40 AM
Interesting article on the role of reticulation in evolution:
"...review tries to draw attention to evolutionary processes that lead to the origin and growth of diversity and complexity in biological systems by reticulations...‘Biology’s Second Law’"
www.mdpi.com/2079-7737/14...
🧪 #EvoBio
1/2
"...review tries to draw attention to evolutionary processes that lead to the origin and growth of diversity and complexity in biological systems by reticulations...‘Biology’s Second Law’"
www.mdpi.com/2079-7737/14...
🧪 #EvoBio
1/2
Eruption of the Hunga Tonga–Hunga Haʻapai in 2022 was a unique phreatic eruption even where we can learn many things on the effects of explosive eruptions on the Earth system.
Eruption was so large that in the atmosphere formed transient ice ring.
www.nature.com/articles/s43...
🧪 ⚒️ #Geology
Eruption was so large that in the atmosphere formed transient ice ring.
www.nature.com/articles/s43...
🧪 ⚒️ #Geology
November 15, 2025 at 5:18 PM
Eruption of the Hunga Tonga–Hunga Haʻapai in 2022 was a unique phreatic eruption even where we can learn many things on the effects of explosive eruptions on the Earth system.
Eruption was so large that in the atmosphere formed transient ice ring.
www.nature.com/articles/s43...
🧪 ⚒️ #Geology
Eruption was so large that in the atmosphere formed transient ice ring.
www.nature.com/articles/s43...
🧪 ⚒️ #Geology
Dogs and other domesticated animals present an unique set of natural-cultural supra-specific diversification under human sorting. Given analysis combined the data on dogs across range of times. Interestingly though, Holocene dogs were diverse!
www.science.org/doi/epdf/10....
🧪 ⚒️ #EvoBio #Paleobio
www.science.org/doi/epdf/10....
🧪 ⚒️ #EvoBio #Paleobio
November 14, 2025 at 8:18 PM
Dogs and other domesticated animals present an unique set of natural-cultural supra-specific diversification under human sorting. Given analysis combined the data on dogs across range of times. Interestingly though, Holocene dogs were diverse!
www.science.org/doi/epdf/10....
🧪 ⚒️ #EvoBio #Paleobio
www.science.org/doi/epdf/10....
🧪 ⚒️ #EvoBio #Paleobio
"we first show that rates of evolution estimated as a parameter in the unbiased random walk model lack a rate–time scaling when data has been generated using this model, even when time series are made incomplete and biased."
🧪 ⚒️ #EvoBio #Paleobio
academic.oup.com/evolut/advan...
🧪 ⚒️ #EvoBio #Paleobio
academic.oup.com/evolut/advan...
November 13, 2025 at 2:19 PM
"we first show that rates of evolution estimated as a parameter in the unbiased random walk model lack a rate–time scaling when data has been generated using this model, even when time series are made incomplete and biased."
🧪 ⚒️ #EvoBio #Paleobio
academic.oup.com/evolut/advan...
🧪 ⚒️ #EvoBio #Paleobio
academic.oup.com/evolut/advan...
Biological accommodation of climatic variability is a first order factor enabling success of species. An excellent study of temperature niche breadth and geographical ranges of terrestrial plants.
doi.org/10.1073/pnas...
🧪 ⚒️ #EvoBio #Paleobio #Macroecology
doi.org/10.1073/pnas...
🧪 ⚒️ #EvoBio #Paleobio #Macroecology
November 13, 2025 at 2:02 PM
Biological accommodation of climatic variability is a first order factor enabling success of species. An excellent study of temperature niche breadth and geographical ranges of terrestrial plants.
doi.org/10.1073/pnas...
🧪 ⚒️ #EvoBio #Paleobio #Macroecology
doi.org/10.1073/pnas...
🧪 ⚒️ #EvoBio #Paleobio #Macroecology
November 9, 2025 at 9:56 PM
This illustration from a classic, reminds us, that we need all three approaches to the ancient worlds:
Palæontography - the description of past life forms
Palæobiology - purely biological theoretical outlook
Palæontology - a holistic study of the past, combining different fields.
🧪 ⚒️ #Paleobio
Palæontography - the description of past life forms
Palæobiology - purely biological theoretical outlook
Palæontology - a holistic study of the past, combining different fields.
🧪 ⚒️ #Paleobio
November 5, 2025 at 9:16 PM
This illustration from a classic, reminds us, that we need all three approaches to the ancient worlds:
Palæontography - the description of past life forms
Palæobiology - purely biological theoretical outlook
Palæontology - a holistic study of the past, combining different fields.
🧪 ⚒️ #Paleobio
Palæontography - the description of past life forms
Palæobiology - purely biological theoretical outlook
Palæontology - a holistic study of the past, combining different fields.
🧪 ⚒️ #Paleobio
If you need a professional terrestrial phototroph you need a symbiont of plant+fungi. Lichen (Spongiophyton sp) colonized the land already at least in the Early Devonian:
www.science.org/doi/10.1126/...
🧪 ⚒️ #Paleobio #EvoBio #Geology
www.science.org/doi/10.1126/...
🧪 ⚒️ #Paleobio #EvoBio #Geology
November 3, 2025 at 3:03 PM
If you need a professional terrestrial phototroph you need a symbiont of plant+fungi. Lichen (Spongiophyton sp) colonized the land already at least in the Early Devonian:
www.science.org/doi/10.1126/...
🧪 ⚒️ #Paleobio #EvoBio #Geology
www.science.org/doi/10.1126/...
🧪 ⚒️ #Paleobio #EvoBio #Geology
Eva sends best regards from her kindergarten!
October 31, 2025 at 1:24 PM
Eva sends best regards from her kindergarten!
Historical reflection by a legendary biometrician, morphometrists, and statistician F. James Rohlf on the emergence of mathematization of the classification and systematics during his life time.
academic.oup.com/sysbio/advan...
🧪 ⚒️ #Paleobio #EvoBio
academic.oup.com/sysbio/advan...
🧪 ⚒️ #Paleobio #EvoBio
October 31, 2025 at 1:18 PM
Historical reflection by a legendary biometrician, morphometrists, and statistician F. James Rohlf on the emergence of mathematization of the classification and systematics during his life time.
academic.oup.com/sysbio/advan...
🧪 ⚒️ #Paleobio #EvoBio
academic.oup.com/sysbio/advan...
🧪 ⚒️ #Paleobio #EvoBio
From the depths of the Wikipedia on the character of Paul Dirac:
"Dirac was known among his colleagues for his precise and taciturn nature. His colleagues in Cambridge jokingly defined a unit called a "dirac", which was one word per hour."
What's your apparent flow in "diracs"?
"Dirac was known among his colleagues for his precise and taciturn nature. His colleagues in Cambridge jokingly defined a unit called a "dirac", which was one word per hour."
What's your apparent flow in "diracs"?
October 30, 2025 at 3:52 PM
From the depths of the Wikipedia on the character of Paul Dirac:
"Dirac was known among his colleagues for his precise and taciturn nature. His colleagues in Cambridge jokingly defined a unit called a "dirac", which was one word per hour."
What's your apparent flow in "diracs"?
"Dirac was known among his colleagues for his precise and taciturn nature. His colleagues in Cambridge jokingly defined a unit called a "dirac", which was one word per hour."
What's your apparent flow in "diracs"?
The story of extinctions and population depletions in the late Quaternary is a complex one. Climate and humans interference in shaping diversity is always convoluted. Here is the story from the Australian lizards' point of view 👇
www.cell.com/current-biol...
🧪 ⚒️ #Paleobio #Macroecology
www.cell.com/current-biol...
🧪 ⚒️ #Paleobio #Macroecology
October 30, 2025 at 9:15 AM
The story of extinctions and population depletions in the late Quaternary is a complex one. Climate and humans interference in shaping diversity is always convoluted. Here is the story from the Australian lizards' point of view 👇
www.cell.com/current-biol...
🧪 ⚒️ #Paleobio #Macroecology
www.cell.com/current-biol...
🧪 ⚒️ #Paleobio #Macroecology
Perfect cover for the bovide paleobiology volume.
Stasys Eidrigevičius "Heads", in the 'Stasys' Museum, Panevėžys.
Stasys Eidrigevičius "Heads", in the 'Stasys' Museum, Panevėžys.
October 29, 2025 at 2:26 PM
Perfect cover for the bovide paleobiology volume.
Stasys Eidrigevičius "Heads", in the 'Stasys' Museum, Panevėžys.
Stasys Eidrigevičius "Heads", in the 'Stasys' Museum, Panevėžys.
Wow, this is crazy. Direct megafaunal connections between Europe and North America existed up to the Miocene! Imagine island hopping and strait-crossing rhinos in the Arctic:
🧪 ⚒️ #Paleobio #EvoBio #Geology
www.nature.com/articles/s41...
🧪 ⚒️ #Paleobio #EvoBio #Geology
www.nature.com/articles/s41...
October 29, 2025 at 9:05 AM
Wow, this is crazy. Direct megafaunal connections between Europe and North America existed up to the Miocene! Imagine island hopping and strait-crossing rhinos in the Arctic:
🧪 ⚒️ #Paleobio #EvoBio #Geology
www.nature.com/articles/s41...
🧪 ⚒️ #Paleobio #EvoBio #Geology
www.nature.com/articles/s41...
Orca sized lamniform sharks from the Aptian of Australia:
"Our results show that mega-body size is an ancient lamniform trait, with the Australian cardabiodontid being around 6–8 m and over 3 tons."
"Our results show that mega-body size is an ancient lamniform trait, with the Australian cardabiodontid being around 6–8 m and over 3 tons."
October 26, 2025 at 8:51 PM
Orca sized lamniform sharks from the Aptian of Australia:
"Our results show that mega-body size is an ancient lamniform trait, with the Australian cardabiodontid being around 6–8 m and over 3 tons."
"Our results show that mega-body size is an ancient lamniform trait, with the Australian cardabiodontid being around 6–8 m and over 3 tons."
Glad to announce that at our department we will have yet another post-doc — Misha Whittingham @deathandtaxa.bsky.social . His theme of research will be "An exploration of community assembly mechanisms, paleobiogeography, and evolutionary dynamics in Silurian graptolites (Hemichordata)".
October 24, 2025 at 7:57 PM
Glad to announce that at our department we will have yet another post-doc — Misha Whittingham @deathandtaxa.bsky.social . His theme of research will be "An exploration of community assembly mechanisms, paleobiogeography, and evolutionary dynamics in Silurian graptolites (Hemichordata)".
Giant ground sloths had unique food preferences:
"DMTA of Paramylodon harlani ... and Nothrotheriops shastensis ... suggests that P. harlani consumed significantly harderfoods (e.g. tubers, roots, seeds, fruit pits) than N. shastensis."
royalsocietypublishing.org/doi/epdf/10....
🧪 ⚒️ #Paleobio
"DMTA of Paramylodon harlani ... and Nothrotheriops shastensis ... suggests that P. harlani consumed significantly harderfoods (e.g. tubers, roots, seeds, fruit pits) than N. shastensis."
royalsocietypublishing.org/doi/epdf/10....
🧪 ⚒️ #Paleobio
October 23, 2025 at 2:26 PM
Giant ground sloths had unique food preferences:
"DMTA of Paramylodon harlani ... and Nothrotheriops shastensis ... suggests that P. harlani consumed significantly harderfoods (e.g. tubers, roots, seeds, fruit pits) than N. shastensis."
royalsocietypublishing.org/doi/epdf/10....
🧪 ⚒️ #Paleobio
"DMTA of Paramylodon harlani ... and Nothrotheriops shastensis ... suggests that P. harlani consumed significantly harderfoods (e.g. tubers, roots, seeds, fruit pits) than N. shastensis."
royalsocietypublishing.org/doi/epdf/10....
🧪 ⚒️ #Paleobio
Continental arcs a factor in the Cambrian Explosion:
subduction-driven...accelerated erosion of phosphorus-rich juvenile rocks, releasing nutrients that boosted marine productivity and subsequent oxygen buildup through organic burial
www.nature.com/articles/s41...
🧪 ⚒️ #Paleobio #EvoBio #Geology
subduction-driven...accelerated erosion of phosphorus-rich juvenile rocks, releasing nutrients that boosted marine productivity and subsequent oxygen buildup through organic burial
www.nature.com/articles/s41...
🧪 ⚒️ #Paleobio #EvoBio #Geology
October 21, 2025 at 2:33 PM
Continental arcs a factor in the Cambrian Explosion:
subduction-driven...accelerated erosion of phosphorus-rich juvenile rocks, releasing nutrients that boosted marine productivity and subsequent oxygen buildup through organic burial
www.nature.com/articles/s41...
🧪 ⚒️ #Paleobio #EvoBio #Geology
subduction-driven...accelerated erosion of phosphorus-rich juvenile rocks, releasing nutrients that boosted marine productivity and subsequent oxygen buildup through organic burial
www.nature.com/articles/s41...
🧪 ⚒️ #Paleobio #EvoBio #Geology
Glad to announce that at our department of Geology and Mineralogy at Vilnius University we will have a new post-doc—Jason Pardo @jdpardo.bsky.social, who will work on applying the Bretskyan hierarchy paradigm in understanding "The Roles of Space and Time in Palaeozoic Vertebrate Community Assembly"
October 20, 2025 at 8:28 PM
Glad to announce that at our department of Geology and Mineralogy at Vilnius University we will have a new post-doc—Jason Pardo @jdpardo.bsky.social, who will work on applying the Bretskyan hierarchy paradigm in understanding "The Roles of Space and Time in Palaeozoic Vertebrate Community Assembly"
These are Otolithes of the Miocene small cod species Gadiculus labiatus.
October 16, 2025 at 9:15 PM
These are Otolithes of the Miocene small cod species Gadiculus labiatus.