![\"A](\"https:\/\/cdn.sci.news\/images\/enlarge13\/image_14542e-Trilobite.jpg\")
<\/a><\/p>\nA trilobite fossil. Image credit: Elizabeth Bailey \/ University of Texas at San Antonio.<\/p>\n
Chitin is one of the most abundant organic polymers produced by life on Earth, second only to cellulose.<\/p>\n
\u201cThis study adds to growing evidence that chitin survives far longer in the geologic record than originally realized,\u201d said Dr. Elizabeth Bailey, a researcher at the University of Texas at San Antonio.<\/p>\n
\u201cBeyond paleontology, this has significant implications for understanding how organic carbon is stored in Earth\u2019s crust over geologic time.\u201d<\/p>\n
Using fluorescent staining and various spectroscopy techniques, Dr. Bailey and her colleagues analyzed the cuticle of an Olenellus trilobite<\/a> from the Cambrian Carrara Formation<\/a>.<\/p>\n The researchers found spectral peaks indicative of d-glucosamine, the monomer of chitin.<\/p>\n Their result contrasts with many previous analyses that produced a negative detection of chitin in a variety of fossils.<\/p>\n It is also consistent with literature published in recent decades reporting positive chitin detections in fossils using modern analytical techniques.<\/p>\n \u201cThough this study focused on a small number of fossils, the implications reach well beyond trilobites,\u201d the scientists said.<\/p>\n \u201cUnderstanding how organic carbon can persist in common geological settings will help us reconstruct Earth\u2019s carbon cycle and may inform how carbon is stored naturally within the planet\u2019s crust.:<\/p>\n \u201cThe research also has potential relevance for modern climate discussions,\u201d they noted.<\/p>\n \u201cFor instance, limestones, which are formed from accumulated biological remains and widely used as building materials throughout human history, often contain chitin-bearing organisms.\u201d<\/p>\n \u201cWhen people think about carbon sequestration, they tend to think about trees,\u201d Dr. Bailey said.<\/p>\n \u201cBut after cellulose, chitin is considered Earth\u2019s second most abundant naturally occurring polymer.\u201d<\/p>\n \u201cEvidence that chitin can survive for hundreds of millions of years shows that limestones are part of long-term carbon sequestration and relevant to understanding Earth\u2019s carbon dioxide levels.\u201d<\/p>\n