Eoandromeda

 ( Enigmatic Prehistoric Animal Genera ) 

The organism bears a very superficial resemblance to , and to some of the other Ediacara biota, but it lacks sufficient physical characteristics to ascertain with any degree of certainty whether it is indeed an animal or not. If it is, it would be the earliest known fossil of an adult animal; and its anatomy is consistent with that expected from the earliest animals. However, it is not perfectly clear that it is an animal; algae, the dominant constituent of the Doushantuo biota, cannot be ruled out, except that Eoandromeda seems a little too complex.

• Ediacara-type biota (it is in broad sense: Ediacara-, Nama-, Avalon-type ecological assemblage) it is community of the Metazoa and problematic organisms: Dickinsonia, Yorgia, Kimberella, Charnia, Charniodiscus, Cyclomedusa, Ediacaria, Parvancorina, Pteridinium, Rangea, Fractofusus, Tribrachidium, Hiemalora, Palaeopascichnus and others. These organisms mainly are negative and positive imprints on the base of sandstone beds with the "elephant skin" and tubercle texture diagnostic of (Ediacara-type preservation), sandy casts in the beds of sandstone (Nama-type preservation), Avalon-type preservation characterized imprints on the top mudstone surface covered by volcanic ash, and in Khatyspyt-type preservation the fossils are found in finely laminated to medium-bedded, nodular bituminous limestones.
• Miaohe-type biota characterizes assemblage of algal macrofossils: Beltanelloides, Mezenia, Sinospongia, Jiuqunaoella, Grypania, Liulingjitaenia, Tawuia, Calyptrina, Cucullus and others. These fossils are of the form of flat organic carbonaceous films; it is shadow left by organic matter of the organism flesh (it is looks like of the Burgess shale type preservation).

Trying to relate organisms that are preserved in the two modes is immensely problematic, because they preserve such different parts of organisms; the imprints preserve a casts of the organism's outline, whereas the carbonaceous films display a shadow left by any resistant organic matter. This has made relating the two taphonomic types very difficult: Eoandromeda is one of the few organisms which can convincingly be compared in both taphonomic modes. Such cases of preservation are known also for organisms related to the Anfesta-Albumares-like fossils from the Doushantuo Formation, for Beltanelloides from the Lyamtsa Formation of the White Sea area, Russia and Doushantuo Formation, and possible for Cyclomedusa from Perevalok Formation of the Urals.

• List of Ediacaran genera