doi.org/10.1139/cjz-2025-0109
Credibility: 989
#Fossils
Scientists have just revealed surprising details about the evolution of the first fish that inhabited Earth more than 400 million years ago, thanks to two independent studies conducted by teams from Australia and China
These studies focus on ancient lungfish, the closest living relatives of vertebrates that eventually left the water to conquer land, giving rise to tetrapods-a group that includes amphibians, reptiles, birds, and mammals, including us humans.
Lungfish are fascinating because they already possessed primitive lungs, allowing them to breathe air in oxygen-poor waters, a crucial adaptation for the transition to terrestrial life.
Now, using advanced computed tomography (CT) imaging, researchers have examined rare and exceptionally well-preserved fossils from the Devonian period, an era when life was rapidly diversifying in the oceans and beginning to explore the continents.
In Australia, at the famous Gogo Formation in the west of the country, the team reanalyzed the enigmatic fossil called Cainocara, a lungfish from the Late Devonian.
Digital scans revealed the external and internal skull in impressive detail, correcting previous interpretations about its orientation and showing similarities to other lungfish from the same region, such as Chirodipterus australis.
These images highlight primitive and derived characteristics in the evolution of lobe-finned fish, an ancestral group of tetrapods, and clarify how complex the brain cavity and inner ear were even in very ancient forms.
In China, another study described a new lungfish skull, named Paleolophus yunnanensis, dated to about 410 million years ago, found in rocks in the south of the country.
This fossil shows unique feeding adaptations and a cranial structure that indicates a rapid diversification of these fish early in the Devonian.
Together, the two findings demonstrate that lungfish were more varied and anatomically sophisticated than previously thought, with traits that emerged in aquatic environments even before the great explosion of terrestrial forms.
These discoveries challenge previous views on the transition from water to land, showing that many of the necessary evolutionary ingredients-such as functional lungs, robust fins, and complex cranial structures-were already present and developing in aquatic fish during the early, middle, and late Devonian periods.
Instead of a gradual and linear change, there appears to have been accelerated and diverse evolution among these ancestral fish, paving the way for some descendants to adapt to life on land.
Researchers like Dr. Alice Clement of Flinders University in Australia explain that these fossils add important pieces to the puzzle of the evolution of early lobe-finned fish.
Dr. Brian Choo highlights how this evidence reveals insights into the rapid evolutionary diversification during this crucial period.
The results were published in respected scientific journals: one in the Canadian Journal of Zoology and another in Current Biology.
Ultimately, these fossil fish, over 400 million years old, not only enrich our understanding of the distant past, but also show how small anatomical innovations in ancient aquatic creatures opened the doors to the conquest of land by vertebrates, forever changing the history of life on the planet.
Published in 02/15/2026 02h13
Text adapted by AI (Grok) and translated via Google API in the English version. Images from public image libraries or credits in the caption. Information about DOI, author and institution can be found in the body of the article.
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