Charnia is a genus of frond-like lifeforms belonging to the Ediacaran biota with segmented, leaf-like ridges branching alternately to the right and left from a zig-zag medial suture. The genus Charnia was named for Charnwood Forest in Leicestershire, England, where the first fossilised specimen was found. Charnia is significant because it was the first Precambrian fossil to be recognized as such.
A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the large leaves of cycads, as well as palms (Arecaceae) and various other flowering plants, such as mimosa or sumac. "Frond" is commonly used to identify a large, compound leaf, but if the term is used botanically to refer to the leaves of ferns and algae it may be applied to smaller and undivided leaves.
The rangeomorphs are a form taxon of frondose Ediacaran fossils that are united by a similarity to Rangea. Some researchers, such as Pflug and Narbonne, suggest that a natural taxon Rangeomorpha may include all similar-looking fossils. Rangeomorphs appear to have had an effective reproductive strategy, based on analysis of the distribution pattern of Fractofusus misrai, which consisted of sending out a waterborne asexual propagule to a distant area, and then spreading rapidly from there, just as plants today spread by stolons or runners.
Charniodiscus is an Ediacaran fossil that in life was probably a stationary filter feeder that lived anchored to a sandy sea bed. The organism had a holdfast, stalk and frond. The holdfast was bulbous shaped, and the stalk was flexible. The frond was segmented and had a pointed tip. There were two growth forms: one with a short stem and a wide frond, and another with a long stalk, elevating a smaller frond about 50 centimetres (20 in) above the holdfast. While the organism superficially resembles the sea pens (cnidaria), it is probably not a crown-group animal.
Rangea is a frond-like Ediacaran fossil with six-fold radial symmetry. It is the type genus of the rangeomorphs.
Thectardis avalonensis is a triangular-shaped member of the Ediacaran biota, dating from 574 to 565 million years ago. The organism took the form of an elongated cone with a central depression, and its apex was anchored to the substrate.
The Ediacaranbiota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period. These were enigmatic tubular and frond-shaped, mostly sessile, organisms. Trace fossils of these organisms have been found worldwide, and represent the earliest known complex multicellular organisms. The term "Ediacara biota" has received criticism from some scientists due to its alleged inconsistency, arbitrary exclusion of certain fossils, and inability to be precisely defined.
Conulariida are an extinct group of medusozoan cnidarians known from fossils spanning from the latest Ediacaran up until the Late Triassic. They are almost exclusively known from their hard external structures, which were pyramidal in shape and made up of numerous lamellae.
Pectinifrons was a rangeomorph, a member of the Ediacara biota found at Mistaken Point, Newfoundland.
Arborea is a genus of Petalonamid that was originally considered as being synonymous with Charniodiscus. It consisted of a frond-like body 3–4 inches (7.6–10.2 cm) long that was attached to the substrate via a Holdfast that possessed many concentric rings on it. Species which were thought to have been within the genus Charniodiscus are now being interpreted as belonging to the genus Arborea with the latter of which being considered synonymous with Charniodiscus. A. arborea was first described from South Australia, and is the most abundant Petalonamid in the Flinders Ranges. The genus currently contains 5 known species with 3 of them originally being species of Charniodiscus; the species include A. arborea, A. denticulata, A. longa, A. oppositus and A. spinosa.
Avalofractus abaculus is a frond-like rangeomorph fossil described from the Ediacaran of the Trepassey Formation, Spaniard's Bay, Newfoundland.
Beothukis mistakensis is a rare fossil frond-like member of the Rangeomorpha, described from the Ediacaran of Mistaken Point, Newfoundland. It had been identified since 1992, referred in papers as a "spatulate frond" or "flat recliner", but not formally described until 2009. The original fossils from which the genus has been described are still in situ, but replicas are preserved at the Memorial University of Newfoundland and at the Oxford University Museum of Natural History. Claims of a stem have been contentious, and based largely on structures that have subsequently been determined to be erosional scours, and is so considered to be a recliner
The Mistaken Point Formation is a geologic formation in Newfoundland and Labrador. It is recognized as a Lagerstätte preserving fossils dating back to the Ediacaran period. It contains a stratum dated to 565 ± 3 million years ago.
The Fermeuse Formation is a fossil-bearing Ediacaran geologic formation in Newfoundland.
Parviscopa is a genus of frondose forms characterized in 2008 based on specimens from Newfoundland, Canada. Parviscopa is a member of the Ediacaran biota, and is more specifically part of the Avalon type assemblage, which is from the older part of the Ediacaran and is characterized by deep water deposits.
Frondosity is the property of an organism that normally flourishes with fronds or leaf-like structures.
Trepassia is a 579 million-year-old fossil of Ediacaran rangeomorph. It was first discovered by Guy M. Narbonne, a professor at Queen's University in Ontario, Canada and colleagues in 2009. Three years later, Martin D. Brasier added additional description to Trepassia. The generic name is taken from the French word, trépassés, which translates to "those that have departed forever" and honors the Trepassey community in Newfoundland. It was originally described as Charnia wardi; it was referred under this synonym in a 2016 paper.
Frondophyllas, also referred to Xmas tree, is an extinct, monotypic animal genus in the clade Rangeomorpha. It was found at the Mistaken Point on the Avalon Peninsula in Newfoundland, Canada in 2008 by Bamforth and Anderson. The single species is Frondophyllas grandis and as of 2021 only two specimens have been discovered. Both specimens are incomplete, but one extends to one meter long, making it one of the largest Ediacaran macrofossils. The species name: grandis, comes from its size, and the genus name: Frondophyllas means "frond with leaves". The organism has a base structure with numerous fronds attached to it. It is the only Ediacaran organism to have distinct leaflets. Evidence suggests that F. grandis may have been tethered to the seafloor and used these leaflets to "filter feed", or live off nutrients provided by a current. One of the reasons fossils of this species are so rare is because it was a soft-bodied organism. It is believed that F. grandis was preserved because it was caught beneath quickly solidifying volcanic ash. Many of the Mistaken Point fossils were preserved this way.
Hapsidophyllas is a rare Ediacaran rangeomorph fossil found at Mistaken Point, Newfoundland, Canada. It was first identified by Emily Bamforth and Guy Narbonne in 2009. Its name comes from the Greek words for “a network of leaves.” Because its characteristic flexible leaflet structure is dissimilar to other known rangeomorphs, Bamforth and Narbonne describe it as a new rangeomorph form, called hapsidophyllid. The only other known hapsidophyllid is the Ediacaran frond Frondophyllas grandis, which shares the network-like configuration of leaflets seen in Hapsidophyllas. Currently, the Hapsidophyllas flexibilis holotype resides in its type locality in the Mistaken Point Ecological Reserve, and a cast of the specimen is on display at the Royal Ontario Museum in Toronto, Canada.
