Duncan McIlroy

@dmcediacaran.bsky.social

Ediacaran palaeobiologist at Memorial University of Newfoundland. Working on beautiful fossils in Newfoundland & UK alongside amazing students/colleagues with strong local community partnerships to support GeoEducation GeoConservation & ethical GeoTourism

sunburst like Hiemalora with small central disc on a bedding surface with indeterminate circular features (?shafts) scale is in cm.

The inner meadow fossil site showing the size of the excavation and preparation for making of a silicone mold (plasticene dams). The site is on private land with no public access for now (but watch this space)

Stem of a “Primocandelabrum” emerging from a small disc (top right) lying atop a factually branching elongate leaf-like Trepassia with base bottom right and handled towards the top left. Image is retrodeformed approximately

large deep basal (probably holdfast) disk of an unknown irganism. Dish shaped and concentric ally ringed. Finger for scale with battered fingernail.

leaf like (spatulas) fossil on a bubbly bedding surface

split boulder at inner meadow with chisel.

geologists looking at fossils on 560 million year old seafloor in Little Catalina Discovery geopark

the excavation at inner meadow the white rock surface is covered by soil full of rocks some of which contain Ediacaran fossils

graduate student Heléna getting down to the fossil surface with the hose at inner meadow

scratch marks like tubular fosskils with chatter marks and grooves

a mixture of concentric disks and rows of chambers on an Ediacaran bedding plane rock surface

weird branching burrows or borings in a mudstone branching is commonly orthogonal to the long axes. Burrow/boring width is about 0.25mm

A bedding surface with lots of little holes (gas bubbles formed beneath a microbial mat) and a pointy ended frond of Arborea spinosa with a large disc (bottom) and a above us a bushy/tree-shaped frond of Primocandelabrum, also with basal holdfast disc

detail of the InnerMeadow fossil surface with abundant negative hemispherical “bubbles” and a specimen of a vermiform (worm-like) fossil of #Uncus

negative bubbly textures with millimetric aggregations of bubbles either in strips or widespread on Ediacaran bedding planes. Some of which have exceptionally preserved fossils of soft-bodied organisms

$reconstruction of the seafloor at Inner Meadow with matgrounds and leaf like fractal Charnia brasieri in inferred life position (c)duncan mcilroy$

subtriangular multi branched probably rangeomorph frond bradgatia-like foot for scale

reconstruction of Arborea elegans as a long narrow upright frond on a microbially colonized seafloor (white rings)

broad Charnia frond at the bottom with a narrow frond right at its tip lying in the same orientation

bedding surface with large hemispherical Nimbia and several varieties of the chambered Palaeopascichnus gracilis and narrow P. linearis

Comparison of the frondose features in the Dongpo Formation with uninterrupted chevron marks (A−D) and the Ediacaran Charnia for comparison (E). (A) Uninterrupted chevron marks from the Carboniferous Gull Island Formation, Ireland (modified from Doyle and Hoey, 2022); (B) and (D) frondose forms from the Dongpo Formation (modified from Wang et al., 2026); (C) uninterrupted chevron marks from the Lower Silurian Aberystwyth Grits, Wales (modified from Dżułyński and Walton, 1965); (E) Charnia ewinoni from the Ediacaran of Newfoundland (modified from Pasinetti et al., 2025). All scale bars are 1 cm. Portions of the branch-like structures highlighted in (B-D), primary branches in (E) are offset not opposite and have second (red) and third order branches (green) highlighted as is typical of Ediacaran rangeomorphs.

unnamed elongate Arboreomorph frond with broad flat disc numerous small branches arise from a central axis at a high angle

ovoid Aspidella terranovica with central groove next to 3 lobed Triforillonia

This is a bush like Primocandelabrum, perhaps the best one in Newfoundland, it has a big disc and poorly preserved stem. Under study by MSc student Helena Muirhead-Hunt at the moment

Charniodiscus procerus with a long stem, large disc, and a frond that has the typical U shaped branches that cross a central axis

red is the Avalon assemblage the chart shows diversity (dark prior to this paper and lighter including our data. note that it ranges to the end of the dark blue White Sea Assemblage and many of those taxa go extinct at the junction with the Nama Assemblage at 550Ma

$a fan shaped fossil of Plumeropriscum centre, not the best specimen known but it has the fractal branching in the crown typical of the genus Dark areas are glacially polished.$

$A lovely little Trepassia like a long narrow leaf with fractal-like branches$

leaf shaped fossils of Charnia brasieri and Trepassia sp.

branching leaf like fronds and a double tire track like form with transverse bars right

long narrow arborea sp. frond with flat round disc

photo of the paratype of Aninoides it is leaf shaped with primary branches at an acute angle to the axis made of smaller similar branches

$three images of a leaf shaped fossil with low angle first order branches and fractal like higher order branches left is photo of a replica (mold of the lower surface) middle is interpretive drawing and right is a plan view of the inferred top of the same fossil$

$spindle shaped #Trepassia fossil with fractal like branches on a whitish rusty bedding plane overlain with a white volcanic ash$

ediacaran frond with long first order branches like the tail of a comet
the disc at the base is accidental

a comet shaped fossil on a bedding plane with cm scale bar. has an accidental disc on one end. it has very long branches at a low angle to the axis composed of smaller branches similar to #Charnia

Leaf like fossil with zigzagged axis branches meet the axis at a steep angle, are curved (falcate) with transverse second order branches

specimen of C grandis showing rhomboidal branching plaster cast at The Rooms

3d model of the inferred form of Charnia brasieri

Prof Martin Brasier and Dr Jack Matthews enjoying the Upper Island Cove fossil site

leaf shaped animal fossil with sickle shaped branches meeting a a zigzagged axis Charnia brasieri sp nov

$fractal like branches in 3 rows attributed to #Beothukis mistakensis. Fossil is a latex mold so what the bottom of the organism would have looked like if you had pulled it off the seafloor. From Mistaken Point Newfoundland$

two charnias lying in a matground the fronds are living reclined on the seafloor (procumbent) and have falcate primary order branches that we interpret as having curved up above the seafloor, becoming the classic charnia shape in 3D

fossil with alternating falcate branched with 2 orders of smaller rangeomorph branches. it is a negative relief on top of a grey siltstone.

$video of a grey fossil surface with a leaf like fractal frond of Fractofusus with some Bradgatia like biserial branching$

$depiction of #ediacaran microbe covered seafloor reclaiming (pink) fractofusus necromass being simultaneously overgrown by a papillate yellow sponge relative #Lydonia jiggamintia$