Sprecher
Beschreibung
Here we present coccolith imprint, or “ghost”, fossils preserved on the surfaces of palynomorphs. These unusual fossils have now been found on pollen, dinoflagellate cysts, prasinophyte algae, and acritarchs (in this case, probably green algae). Following a review of, to our knowledge, all known reports of coccolith imprints, we show that these fossils occur globally and have been found in every geologic period since the appearance of coccoliths in the Triassic. The fossils themselves are difficult to distinguish under light microscopy and generally appear as small round- or oval-shaped features on palynomorph surfaces. Indeed, caution should be applied when identifying these fossils since they can closely resemble, and therefore easily be mistaken for, a range of features, including apertures, surface ornamentation and pyrite framboid voids. However, fluorescence microscopy can assist in their identification, and scanning electron microscopy can unequivocally reveal their presence. This study highlights the utility of the traditional palynological method to calcareous nannofossil research. With this approach, we emphasize the need for increased awareness of coccolith imprints preserved on palynomorphs, but also demonstrate how their occurrence can help with biostratigraphy and reconstructions of past environments.