An enigmatic, ancient organism that has baffled researchers for more than a decade, might lead to the discovery of its place in the evolutionary tree. Palaeospondylus gunni was found in fossils in Scotland in 1890 and flourished roughly 390 million years ago throughout the Middle Devonian.
Extinct Creature Continues to Puzzle Scientists
As posted under the journal Nature, a recent examination of well-preserved remains, experts believe it was among of the oldest progenitors of tetrapods - creatures with four extremities, including humans.
Daisy (Yuzhi) Hu of the Australian National University explained that this odd species has perplexed researchers before its finding in 1890 as an unsolvable enigma.
Morphometric analogies of this living creature are often exceptionally hard for experts, but new progress in high-resolution 3D fragmentation and modeling have formed this heretofore unattainable goal feasible; obtaining a workpiece as well maintained as the ones researchers utilized is like hitting the jackpot, as per Science Alert.
There are various explanations why categorizing this species has been difficult. It has many remains, however since Palaeospondylus was so little and its bones were so destroyed, recreating its skull morphology was extremely challenging.
Furthermore, its morphology has characteristics with both jawed and jawless fish, as well as an absolute absence of molars and epidermal skeleton retained in the archaeological evidence.
The expert panel, led by paleontologist Tatsuya Hirasawa of the College of Tokyo and RIKEN in Japan, tried to tackle these issues by locating remarkable samples with skulls that were nonetheless securely entrenched and covered in stone.
In comparison to specimens with uncovered skulls, this showed that the skulls of creatures were most often undamaged. By selecting the finest samples for the micro-CT scanning and meticulously clipping off the stone around the ancient cranium, scientists were able to increase the diagnostic sensitivity. Albeit not cutting-edge innovation, these measures were undoubtedly critical to our success.
The scientists next examined the specimens using synchrotron radiation X-ray micro-computed scanning, which enabled them to photograph the relics in great detail sans harming them, allowing them to undertake a full investigation and renovation.
With or without molars or cutaneous tendons, the outcomes are rather remarkable. The scientists discovered three curving tubes in the cranium of Palaeospondylus, which are compatible with the vestibular system of mouthed animals.
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Extinct Creature Related to Human's Ancient Ancestors
Certain aspects of Palaeospondylus' cranium were similar to those of two additional archaic, roughly simultaneous fish, Eusthenopteron and Panderichthys.
Several of these species are classified as lobe-finned fishes, or Sarcopterygians. Most tetrapods descended from Sarcopterygians, and these Sarcopterygians and their tetrapod offspring are referred to as tetrapodomorphs. Eusthenopteron and Panderichthys shared characteristics with tetrapodomorphs.
However, the absence of fangs and epidermal ridges on Palaeospondylus is an issue. These characteristics are typical of tetrapodomorphs, and other species that lived alongside our unusual little fish possessed them as well.
Palaeospondylus appears to be a young tetrapodomorph, lacking any mature characteristics. This might be addressed if Palaeospondylus followed an alternative development change, one that slowed or stopped growing.
It is uncertain if molars and mandible were just delayed to grow or were eliminated totally, however the experts think it might be an environmental oddity that enabled the creature to evolve in various directions, possibly into the formation of appendages.
In the future, the specialists want to extend their investigation into the peculiar organism in attempt to further firmly determine its location in the mammalian genealogy.
From a formative evolutionary standpoint, the odd shape of Palaeospondylus, which is akin to that of tetrapod caterpillars, is really fascinating.
With this in mind, EureAlert reported that researchers shall proceed to investigate the embryonic mechanics that resulted in this and similar morphological alterations that happened throughout the water-to-land shift in vertebrates' antiquity.
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