''Hylaecullulus fordi'' is a species of

Ediacaran The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and th ...

petalonamid from the

Charnwood Forest Charnwood Forest is a hilly tract in north-western Leicestershire, England, bounded by Leicester, Loughborough and Coalville. The area is undulating, rocky and picturesque, with barren areas. It also has some extensive tracts of woodland; i ...

Leicestershire Leicestershire ( ; postal abbreviation Leics.) is a ceremonial and non-metropolitan county in the East Midlands, England. The county borders Nottinghamshire to the north, Lincolnshire to the north-east, Rutland to the east, Northamptonshire t ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

that serves as an important

rangeomorph The rangeomorphs are a form taxon of frondose Ediacaran Ediacaran biota, 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-look ...

because of its multifoliate anatomy, known from its fossils. Its overall

body plan A body plan, ( ), or ground plan is a set of morphological features common to many members of a phylum of animals. The vertebrates share one body plan, while invertebrates have many. This term, usually applied to animals, envisages a "blueprin ...

is similar to that of a

goblet A chalice (from Latin 'mug', borrowed from Ancient Greek () 'cup') or goblet is a footed cup intended to hold a drink. In religious practice, a chalice is often used for drinking during a ceremony or may carry a certain symbolic meaning. Re ...

, from which its name, ''Hylaecullulus'', derives.

Etymology

The name ''Hylaecullulus fordi'' derives from its occurrence within Charnwood Forest: , (which means 'from the woods' in

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

and , which means 'small goblet' in that language. The name of the type species, "fordi", was given to honour

Trevor Ford Trevor Ford (1 October 1923 – 29 May 2003) was a Welsh professional footballer who played as a centre forward for Swansea Town, Aston Villa, Sunderland, Cardiff City, PSV, Newport County and Romford, as well as for the Wales national tea ...

, who made important contributions to the Ediacaran fauna.

Discovery

''Hylaecullulus fordi'' was discovered in the hilly tract of

in 2018 by a team led by C. G. Kenchington. This team found six well-preserved fossils, all of which had fossilised with the lateral view of the animal visible, from the top of the Bradgate Formation of the Maple Group. Although two specimens out of the six fossils found were poorly preserved, they were still assigned to the genus, with all of the specimens being preserved as epirelief (positive relief) impressions. After the discovery of these fossils, master molds were made of them, which are currently being housed within the

British Geological Survey The British Geological Survey (BGS) is a partly publicly funded body which aims to advance geoscientific knowledge of the United Kingdom landmass and its continental shelf by means of systematic surveying, monitoring and research. The BGS h ...

, with the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

s being kept

in situ ''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...

Description

''Hylaecullulus fordi'' represents a multifoliate rangeomorph consisting of a holdfast along with a similarly sized crown, all of which are connected by a straight, proportionally long and narrow stem. The holdfast mainly consists of multiple concentric rings making up a triangular shape at its junction with the stem. The stem is shown as being mainly straight in the fossil specimens, along with being quite uniform in width while also being larger than the crown that sits atop the stem. The crown is multifoliate and has a sub-circular outline comprising multiple folia that all emanate from a single point from the distal-point end of the stem, with the aforementioned folia being either unfurled or furled with signs of them being unconstrained and alongside that, also showing distal inflation. The main branches of the folia show furled, radiating and unconstrained proximal inflation- with unfurled branches being locally present in some specimens. Alongside the main branches, there are also tertiary branches that exhibit furled, constrained and radiation as well as distal inflation. The folia, along with the first- and second-order branches of the crown, may manifest "eccentric branches" which appear at any point in their height these branches all conform to the branching pattern of their host branch, unlike other rangeomorphs, but do not conform to the branching pattern of their neighboring folia.

Measurements

The heights of the known specimens (which are measured from the base of the stem) range from about 7.6cm-37.6cm (2.99213-14.80315 inches). The diameter of the disc ranges from 2.7cm-27cm (1.06299-10.6299 inches) although it increases in proportion with the total height.

Importance

Comparison to other rangeomorphs

''Hylaecullulus fordi'' fossils are distinguished from other rangeomorphs because of its multifoliate nature, that appears only in ''

Bradgatia ''Bradgatia linfordensis'' is a bush-like Ediacaran fossil. It consists of six or more fronds radiating from a central anchor point at the base. It superficially resembles a compressed cabbage in appearance, although in reality it had a more i ...

'' and ''

Primocandelabrum ''Primocandelabrum'' is a genus of rangeomorph known from the Avalon-type Ediacaran biota. It makes up the brunt of some bedding plane assemblages. ''Primocandelabrum'' was described by Hofmann, O'Brien, and King in 2008. Diversity Fossil spe ...

'' -both of which posses the multifoliate nature of ''Hylaecullulus''. These 2 taxa also co-occur alongside fossils of ''H. fordi'' on the Bed B of the Bradgate Formation. Although they both deviate a little from ''Hylaecullulus''. ''Bradgatia'' has a similar multifoliate anatomy, although it lacks a proper stem and instead has a small, bulb-shaped holdfast. The architecture of the branches within ''Bradgatia'' are also distinct from ''Hylaecullulus'' since the folia seen in ''Bradgatia'' are unfurled and show signs of radiation from all resolvable orders of its branching. on the other hand, ''Primocandelabrum'' only superficially resembles ''Hylaecullulus'' this being because it possesses a more anatomically simple holdfast alongside a straight–albeit, proportionally shorter– stem. The bushy crown of ''Primocandelabrum'' distinguishes itself from the crown of ''H. fordi'' because of its notably triangular outline that is preserved along with branches that are coarser and are in the shape of a

Candelabrum A candelabra (plural candelabras) or candelabrum (plural candelabra or candelabrums) is a candle holder with multiple arms. Although electricity has relegated candleholders to decorative use, interior designers continue to model light fixtures ...

. The poor preservation of the type specimens of ''H. fordi'' separate its possible affinity as being a close relative of 'Primocandelabrum'' because the specimens collected from

Newfoundland Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...

render the preservation of their finer branching architecture impossible to determine, although the specimens from

consistently distinguishes it from ''Primocandelabrum''.

Importance to Ediacaran fauna and rangeomorphs

''Hylaecullulus'' presents itself as a representative of a greater architectural complexity alongside truly modern organization of body plans, which hereby also results in highlighting the importance of modularity when evolving to have a large, more complex body-plan in phylogenetically disparate taxa and clades. The evolution of eccentric growth in the form of having eccentric branches shows that they can illustrate their ability to respond to physical, external

stimuli A stimulus is something that causes a physiological response. It may refer to: * Stimulation ** Stimulus (physiology), something external that influences an activity ** Stimulus (psychology), a concept in behaviorism and perception * Stimulus (eco ...

which also result in them conforming to considerable environmental tolerance.

References

{{Reflist Petalonamae Ediacaran Ediacaran life Aquatic animals Ediacaran Europe Enigmatic prehistoric animal genera Fossil taxa described in 2018