Some classics were just made to go together . Peanut butter and umber . Thanksgiving dinner and stint pants . Scleractinian corals and dinoflagellate algae . And boy , do those two go way back — scientists looking at fossils say the two have been cohabit since at least about 212 million years ago , in the Late Triassic Period . The researchers publish their report today in the journalScience Advances .
Happy , healthy coral is essential for a happy , sizable reef . To continue happy and level-headed , many modern corals have forgedsuper close relationshipswith teeny algae calledzooxanthellae . The corals give the alga a safe topographic point to survive and the chemical component for photosynthesis , while the alga make oxygen , keep the water system clean , and produce all kinds of helpful nutrients . The pair really have a serious thing going .
But just how long it ’s been going on has been anybody ’s speculation . old studies on the pair ’s family relationship have been mostly speculative , using data from modern - mean solar day corals to imagine their root ’ globe .
Now , two new scientific techniques , one visual and one chemical substance , have allow us to get a far more exact picture of coral story .
Earlier this year , guide author Katarzyna Frankowiak and a identification number of her co - authorsreportedthat they ’d figure out how to tell if a fossilized heavy red coral had been in a relationship with algae . The trick , they said , is to look very closely at the coral ’s skeleton to see how it had grown and aged . Even when the algae itself was long go , its presence had left irrevocable ( if microscopical ) change in the coral ’s life .
For the new subject , the researchers apply this technique to midget samples of ossified hard corals found near the formerTethys Seain Turkey . They used a diverseness of high - power microscope to analyse the fossil in the most min of point and found that the skeleton of these ancient , ancient samples depend a lot like those of innovative symbiotic hard corals .
Algae bodily process ( brownish loony toons in the tissue , upper left double ) is read in the coral skeleton as morphologic ( development stria ; upper right image ) and geochemical touch . Such regular ontogenesis bands occur in Upper Triassic ( ca . 220 Ma ) scleractinian coral ( lower images ) as well . prototype Credit : Isabelle Domart - Coulon ( upper left ) , Jarosław Stolarski ( upper right , and down in the mouth ikon )
The 2d new method bear on the corals ’ chemical typography . The experience of living with algae alters a red coral ’s very molecules , shift theratioof various oxygen , atomic number 6 , and nitrogen isotope . And just as with the visual inspection , analysis of the fossil corals ’ isotope suggested that they ’d been sharing their lives with zooxanthellae .
Analyzing the coral isotope succumb another insight : the sea in which these buddies lived was likely in pretty poor status . The fossil corals shared a similar ratio of nitrogen isotopes with modern symbiotic Bermuda corals , which are presently struggling in food - starved waters . It ’s possible , the researchers say , that these hard conditions were what inspired the algae and the corals to band together in the first berth .
