500 million year old fossilized brains of sea monsters indicate the evolution of heads

500 year old fossilised brains of two sea monsters are helping the researchers a great deal in understanding the evolution of ancestors of present day arthropods like scorpions lobsters etc. The new research activity focuses on the oval structure or anterior sclerite found  in the heads of ancient arthropods.

• For so many years,the anterior sclerite was some sort of mystery to the researchers because some prehistoric arthropods have it but others don’t have and its location in the head changes, based on the fossils quality.
• Now fossilized brains had helped in solving the mystery.
• Analysis of anterior sclerites in  2 arthropod fossils shows the structure were associated with  bulbous eyes of the creatures,
• The findings gives proof that these oval structures were associated with the nerves originating in the anterior region of the brain.
• It was confirmed by researcher Javier Ortega-Hernandez, a research fellow in paleobiology at the University of Cambridge, London.
• Fossilized brains though being rare are not unheard of in the fossil records.
• Ortega-Hernanadez studied 2 fossils discovered in British Columbia’s Burgress Shale of 20th century.
• The fossils are around 500 to 510 million years old, showing that the animals lived in the Middle Cambrian.
• One type is soft bodied trilobite-type arthropod Helmetia Expansa and other being is submarine shaped one Odaraia alata.
• The presently living arthropods don’t have anterior sclerite, indicating that the heads have changed over period of time.

Fossils— what they are??

• Fossils are preserved remains of plants and animals, that got buried in the rocks and that existed in the remote past.
• Various fossilization process depends on the tissues type and the external conditions.
• Premineralization, casts and moulds, authigenic mineralization, replacement and recrystallization, adpression etc are some process involved.
• Study of fossils is called as paleontology.

Information about Arthropods

• Arthropods are invertebrates with segmented bodies and jointed legs.
• They include arachnids, myriapods,hexapods, crustaceans and trilobites.
• They belong to Phyllum Arthropoda.
• They have cuticle made of alpha chitin.