A General List of the Fauna Together With Illustrations

The following is a list of the Rhynie chert arthropod fauna that have been described to date.

A controversial arthropod known from the remains of a single specimen, Rhyniognatha hirsti (Tillyard 1928), is now believed to be closely related to the pterygote insects based on the structure of it's mandibles (Engel & Grimaldi 2004). Also included for completeness is an arthropod of uncertain affinities; Rhynimonstrum dunlopi (Anderson & Trewin 2003). Discoveries of new elements of the Rhynie fauna have recently been made, and once described and published with be added to this list in due course.

Click on the image thumbnails for a close up.

Trigonotarbids

Species Described from the Rhynie chert

Palaeocharinus rhyniensis
Palaeocharinus hornei
Palaeocharinus tuberculatus
*Palaeocteniza crassipes

*Note: A single specimen of a tiny arachnid described from the chert by Hirst (1923), Palaeocteniza crassipes, as being related to modern trap-door spiders is now regarded as a juvenile trigonotarbid (Selden et al. 1991).

Useful Texts

Hirst 1923; Dunlop 1994, 1996b, Shear et al. 1987; Selden et al. 1991; Fayers et al. 2004

General Features

Extinct arachnids similar in appearance to spiders but lacking spinnerets and possessing a segmented abdomen.

Palaeoecology

Predator, living in terrestrial habitats. Often found in plant-rich beds, occasionally within empty sporangia and hollow plant stems.

Images

Harvestmen

Species Described from the Rhynie chert

Eophalangium sheari

Useful Texts

Dunlop et al. 2003, 2004

General Features

Arachnids lacking a distinct division between the head and body, with a segmented abdomen. Typically possess a small ovoid body with long slender legs.

Palaeoecology

Predator / saprovore / detritivore, living in damp terrestrial habitats, mostly in plant litter.

Image

Longitudinal section through the body of a female harvestman showing the eye tubercle (et), chelicerae (ch), leg coxae (cx), and within the opisthosma the gut trace (g) and ovipositor (ovi). Click on image for a close-up (scale bar = 1mm) (Copyright owned by University of Münster).

Mites

Species Described from the Rhynie chert

Protacarus crani
Protospeleorchestes pseudoprotacarus
Pseudoprotacarus scoticus
Palaeotydeus devonicus
Paraprotocarus hirsti

Useful Texts

Hirst 1923; Dubinin 1962; Bernini 1986

General Features

Very small arachnids that lack a distinct division between the head and the body and have a smooth abdomen.

Palaeoecology

Micro-herbivore / saprovore, living in damp terrestrial habitats, primarily in plant litter and soil. Some probably also fed on sap from living plants. Occasionally found within empty sporangia.

Image

The line drawing of Protacarus crani, showing the whole animal with segmented walking legs (l), pedipalps (p) and chelicerae (c).

Myriapods

Species Described from the Rhynie chert

Crussolum sp.

Useful Texts

Shear et al. 1998; Anderson & Trewin 2003

General Features

A centipede similar to the modern house centipede, possessing strong poison jaws or 'forcipules', long antennae and 15 pairs of long multi-segmented walking legs.

Palaeoecology

Active predator, living in damp terrestrial habitats, such as in soils, plant litter and under stones.

Images

Ventral view of parts of the forcipular segment of Crussolum sp. (A) (scale bar = 1mm). Shown are the coxosternite (cx) with socketed setae (s), 'trochanter' (tr), femuroid (fm) with spine socket (sp), femur (f), tibia (t) and the base of the apical claw (a).

Species Described from the Rhynie chert

Leverhulmia mariae

Useful Texts

Anderson & Trewin 2003

General Features

A small myriapodous arthropod with at least 5 pairs of walking legs, each with densely crowded hairs or setae on the posterior of the last (tarsal) segment.

Palaeoecology

Saprovore / detritivore, living in damp terrestrial habitats, most probably in plant litter.

Image

The gut contents of macerated plant tissue and spores imply that this animal was a detritivore, feeding within plant litter. The one specimen found to date occurs in chert displaying a clotted or 'mulm-like' texture, together with coprolites and fragments of the crustacean Lepidocaris, implying an aquatic setting. This suggests that the animal was probably washed into a small pond where it was pre

Hexapods

Species Described from the Rhynie chert

Rhyniella praecursor

Useful Texts

Hirst & Maulik 1926; Tillyard 1928; Scourfield 1940a,b; Whalley & Jarzembowski 1981

General Features

A springtail (Collembola), with 3 pairs of legs, an abdomen of 6 segments, possessing a furcula or jumping organ on the 4th abdominal segment and a curious ventral tube on the 1st abdominal segment.

Palaeoecology

Saprovore, living in damp terrestrial habitats, particularly in plant litter and soil.

Image

Species Described from the Rhynie chert

Rhyniognatha hirsti

Useful Texts

Hirst & Maulik 1926, Tillyard 1928, Engel & Grimaldi 2004

General Features

The earliest known pterygote insect. Known only from the fragmentary mouthparts of one specimen, comprising a pair of robust mandibles with bladed tooth-like structures. Although fossil evidence is so far lacking, Rhyniognatha may have possessed primitive wings.

Palaeoecology

Comparing the jaws with those of modern insects, Rhyniognatha may have fed on higher plant tissues.

Image

Crustaceans

Species Described from the Rhynie chert

Lepidocaris rhyniensis

Useful Texts

Scourfield 1926 1940c

General Features

A small multi-segmented crustacean with 10 pairs of biramous leaf-like trunk appendages, long biramous antennae with plumose setae and lacking a cephalic shield in adults. Maxillae modified and look like the first 2 pairs of trunk limbs.

Palaeoecology

Micro-herbivore / detritivore, living in ephemeral freshwater ponds.

Image

Reconstruction of Lepidocaris rhyniensis (in this case a female) showing dorsal (left), lateral (centre) and ventral (right) views of the animal. The egg pouch (e) is also shown (after Scourfield 1926) (scale bar = 1mm).

Species Described from the Rhynie chert

Castracollis wilsonae

Useful Texts

Fayers & Trewin 2003

General Features

8mm long, multisegmented crustacean. Thorax of up to 26 somites, each bearing legs. Up to 28 apodous abdominal segments. 2 series of thoracic legs. Anterior series: 11 pairs of long raptorial legs. Posterior series: 10-15 pairs of smaller phyllopodous legs. Head with large mandibles and long, symmetrical, biramous second antennae.

Palaeoecology

Similar to modern Tadpole Shrimps - detritivore / carnivore, living in ephemeral freshwater ponds.

Image

Reconstruction of the crustacean Castracollis wilsonae (Fayers and Trewin 2003), shown with a hypothetical cephalothoracic shield. The animal in the lower right of the image is next to axes of the charophyte Palaeonitella cranii.

Euthycarcinoids

Species Described from the Rhynie chert

Heterocrania rhyniensis

Useful Texts

Hirst & Maulik 1926; Anderson & Trewin 2003

General Features

Multi-segmented arthropod sharing features with crustaceans and myriapods. Body comprises 5 large dorsal segments, each with 2 corresponding ventral segments that bear a pair of multi-segmented legs.

Palaeoecology

Micro-herbivore / detritivore, living in ephemeral freshwater ponds.

Image

Reconstruction of the Rhynie chert euthycarcinoid Heterocrania rhyniensis (scale bar = 2mm) (Anderson & Trewin 2003).

Arthropoda incertae sedis

Species Described from the Rhynie chert

Rhynimonstrum dunlopi

Useful Texts

Anderson & Trewin 2003

General Features

Articulated tubular segments of cuticle, the leading edge of each with a ring of sockets for spines or setae. Sometimes associated with sheets of punctate cuticle and clusters of long robust setae.

Palaeoecology

Unknown