Fossil feathers are usually preserved or embedded in amber as impressions of carbonaceous membranes and lake sediments and marine sediments, but are rarely mineralized. In a new study, paleontologists have examined the mineralised feathers of 30,000 years old Griffon vultures preserved in ash-rich volcanic deposits of the Koli-Albani Volcanic Complex in Rome, Italy. Bird feathers were conserved in three dimensions, conserving tissue ultrastructures such as melanosomes. These ultrastructures are mineralized with nanocrystalline zeolites, a preservation mode that has not been previously reported in fossil soft tissue.
A 30,000-year-old fossil feather of a Griffon vulture preserved in volcanic rocks at the Koli-Albani Volcanic Complex in Rome, Italy. Image credit: Edoardo Terranova.
The fossil vulture was discovered in 1889 near Rome by a local landowner who recognized its incredible preservation.
The entire body was preserved as a three-dimensional impression, with fine details such as the lid of the eye and wing wings.
The new study, led by University College Cork paleontologist Valentina Rossi, shows that feather preservation extends to the pigmented structure of small microscopic feathers.
“Fossil feathers are usually preserved in ancient mudstones laid in lakes and lagoons,” Dr. Rossi said.
“Fossil vultures are preserved in ash deposits, which is very unusual.”
“When analyzing the feathers of fossil vultures, we found ourselves in unknown territory.”
“These feathers are different from what we normally see in other fossils.”
The authors discovered that feathers are preserved in mineral zeolites by analyzing small samples of fossil feathers using electron microscopy and chemical testing.
“Zeolites are silicon and aluminum rich minerals and are common in volcanic and hydrothermal geological environments,” Dr. Rossi said.
“Zeolites can be formed as primary minerals (using clean crystals) or secondary during the natural changes in volcanic glass and ash, giving rocks a mudlock-like side.”
“The changes in ashes due to the passage of water induced precipitation of zeolite nanocrystals, replicating feathers to the details of the smallest cells.”
“Fine preservation of feather structures indicates that vulture corpses were buried in cold thermal clastic matter.”
“We are used to think that volcanic deposits are associated with high temperature, fast-moving thermal breaking flows that destroy soft tissue,” says Professor Dawid Iurino of the University of Milan.
“However, these geological environments are complex and can include cold deposits that can store soft tissue at the cellular level.”
“The fossil record is constantly amazed us with new fossil species, strange new body shapes, in this case a new style of fossil preservation,” said Professor Maria McNamara, a professor of Cork at the University.
“We never found any delicate tissues, such as feathers, preserved in volcanic rocks.”
“Discoveries like these broaden the range of potential rock types that can be found in fossils.
a paper The findings were published in the journal Geological.
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Valentina Rossi et al. Fossil feathers from the Coralbani Volcanic Complex (central Italy, late Pleistocene) preserved in zeolites. GeologicalPublished online on March 18th, 2025. doi: 10.1130/g52971.1
Source: www.sci.news
