A team of scientists identified the oldest known animal sperm in a fossilized cocoon found in Antarctica estimated to be 50 million years old.
According to BBC News, authors of a study published in the journal Biology Letters determined the sample came from an animal family worms and leeches. The researchers described the discovery as surprising given the fleeting nature of sperm.
"Sperms are very transient, very short-lived, with soft cellular structures," study lead author Benjamin Bomfleur, of the Swedish Museum of Natural History, told BBC News. "They are hardly every preserved in the fossil records.
"Plant sperm has been described before, from deposits as old as 400 million years."
Bomfleur and his team will be able to examine the sperm samples and possibly even gather enough data to fill in some evolutionary blanks for insects that create cocoons.
"If it should turn out that we can get this information, all of a sudden we would basically unlock an entire fossil record for a group that hardly had any identifiable fossils before," he told Nature.
Unfortunately, the fossilized sperm yields no DNA that the researchers can extract, meaning there will be cloning of the animal that produced the sample.
"It might appear as if it was preserved in perfect detail but in the end the structure itself is fossilized," Bomfleur told BBC News. "We have the outer shape and form of the sperm cells preserved. We might even have internal, anatomical make-up of the sperm cells still preserved, we are not sure about that yet - we need to scan those using x-ray.
"But even if anatomy should still be preserved, the material that it is composed of is altered so it's not the original, organic material that the past animal sperm is composed of."
