Synchrotron X-ray absorption spectroscopy of melanosomes in vertebrates and cephalopods: implications for the affinity of Tullimonstrum
- Univ. College Cork, Distillery Fields, Cork (Republic of Ireland)
- SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource (SSRL)
- Fujita Health Univ. Toyoake, Aichi (Japan). School of Health Sciences
Screening pigments are essential for vision in animals. Vertebrates use melanins bound in melanosomes as screening pigments, whereas cephalopods are assumed to use ommochromes. In this work, preserved eye melanosomes in the controversial fossil Tullimonstrum (Mazon Creek, IL, USA) are partitioned by size and/or shape into distinct layers. These layers resemble tissue-specific melanosome populations considered unique to the vertebrate eye. Here, we show that extant cephalopod eyes also show tissue-specific size- and/or shape-specific partitioning of melanosomes; these differ from vertebrate melanosomes in the relative abundance of trace metals and in the binding environment of copper. Chemical signatures of melanosomes in the eyes of Tullimonstrum more closely resemble those of modern cephalopods than those of vertebrates, suggesting that an invertebrate affinity for Tullimonstrum is plausible. Melanosome chemistry may thus provide insights into the phylogenetic affinities of enigmatic fossils where melanosome size and/or shape are equivocal.
- Research Organization:
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource (SSRL)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); European Research Starting Grant
- Grant/Contract Number:
- AC02-76SF00515; ERC-2014-StG-637691-ANIVOLEVO
- OSTI ID:
- 1604749
- Journal Information:
- Proceedings of the Royal Society B: Biological Sciences, Vol. 286, Issue 1913; ISSN 0962-8452
- Publisher:
- The Royal Society PublishingCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Hierarchical biota-level and taxonomic controls on the chemistry of fossil melanosomes revealed using synchrotron X-ray fluorescence
Tissue-specific geometry and chemistry of modern and fossilized melanosomes reveal internal anatomy of extinct vertebrates