1) Burgess Shale fossil
Found on
https://www.crosswordclues.com/clue/margaretia
Margaretia is a frondose organism known from the middle Cambrian Burgess shale.{fotbs} Its fronds reached about 10 cm in length and are peppered with a range of length-parallel oval holes. Its original interpretation as a green alga is not secure; it also resembles some alcyonarian corals, but a thorough redescription will be necessary to securely...
Found on
http://en.wikipedia.org/wiki/Margaretia
No exact match found.
