''Edenopteron'' is a genus of large

tristichopterid Tristichopterids (Tristichopteridae) were a diverse and successful group of tetrapodomorph fishes living throughout the Middle and Late Devonian. They first appeared in the Eifelian stage of the Middle Devonian. Within the group sizes ranged from ...

fish from the

Late Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, wher ...

(

Famennian The Famennian is the latter of two faunal stages in the Late Devonian Epoch. The most recent estimate for its duration estimates that it lasted from around 371.1 million years ago to 359.3 million years ago. An earlier 2012 estimate, still used b ...

) of what is now southeastern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. It is known from a single specimen of a single species, ''E. keithcrooki'', described in 2013.

Discovery

Skull and shoulder-girdle restorations of Tristichopterids

''Edenopteron keithcrooki'' is known from remains excavated from the Worange Point Formation, near the town of Eden on the coast of

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

in 2008. The species name is a combination of the name Eden and ''pteron'', meaning wing or fin in Greek. The specific name honors Dr.

Keith Crook Keith Alan Waterhouse Crook (3 August 1933 - 18 February 2020) was an Australian geologist and Clarke Medalist. Education Keith Crook attended Newington College (1944-1949) and the University of Sydney from whence he graduated as a Bachelor of ...

of the

Australian National University The Australian National University (ANU) is a public research university located in Canberra, the capital of Australia. Its main campus in Acton encompasses seven teaching and research colleges, in addition to several national academies and ...

for his discovery of several fossil sites in New South Wales and his key role in helping to map the geology around Eden.

Description

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 ...

consists of numerous semi-articulated remains, including an incomplete

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...

roof, snout, palate, cheeks, lower jaws and associated dermal bones, a left

shoulder girdle The shoulder girdle or pectoral girdle is the set of bones in the appendicular skeleton which connects to the arm on each side. In humans it consists of the clavicle and scapula; in those species with three bones in the shoulder, it consists of t ...

, and assorted

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...

. Reconstructions suggest a skull length of 30 cm (12 in) and lower jaw length of about 48 cm (19 in). The endoskeleton shows a large or complete lack of

ossification Ossification (also called osteogenesis or bone mineralization) in bone remodeling is the process of laying down new bone material by cells named osteoblasts. It is synonymous with bone tissue formation. There are two processes resulting in t ...

. The orbits (eye-sockets) are somewhat triangular rather than oval-shaped. ''Edenopteron'' possessed dentary fangs and

premaxillary The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has ...

tusks, which are presumed to be derived traits for other large tristichopterids. By comparison to body size ratios of other tristichopterid fishes (e.g. ''

Eusthenodon ''Eusthenodon'' (Greek for “strong-tooth” – ''eustheno''- meaning “strength”, -''odon'' meaning “tooth”) is an extinct genus of tristichopterid tetrapodomorphs from the Devonian, Late Devonian period, ranging between 383 and 359 mi ...

'', ''

Langlieria ''Langlieria'' is a genus of prehistoric sarcopterygian (lobe-finned "fish"), from the end of the Devonian period (Famennian). It was discovered in Belgium and Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwe ...

'', '' Mandageria''), the body length of ''Edenopteron'' is estimated at 2.9—3.2 m (9.5—10.5 ft). Additional fossil material may be described in the future: according to lead researcher Gavin Young, quoted in the

Canberra Times ''The Canberra Times'' is a daily newspaper in Canberra, Australia, which is published by Australian Community Media. It was founded in 1926, and has changed ownership and format several times. History ''The Canberra Times'' was launched in ...

: "We know that part of the pectoral girdle is still in the rock, so if we can lift up a few more blocks, we might find that the body is actually preserved in the rock."

Classification

''Edenopteron'' is assigned to the Gondwanan tristichopterid subfamily Mandageriinae due to similarities shared with ''

Cabonnichthys ''Cabonnichthys'' ("Burns' Cabonne fish") is an extinct genus of tristichopterid fish that lived in the Late Devonian period (Famennian) of Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign c ...

'' and '' Mandageria'', including paired

vomer The vomer (; lat, vomer, lit=ploughshare) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxill ...

s in the palate, submandibular bones overlapping ventral jaw margin, and scales ornamented with widely-spaced grooves.

References

External links

Local dig uncovers new species of ancient fish
ANU Media Release
Fang the fish shocks researchers
''The Australian'' {{Taxonbar, from=Q15720781 Tristichopterids Prehistoric lobe-finned fish genera Late Devonian animals Late Devonian fish Prehistoric fish of Australia Paleontology in New South Wales Fossil taxa described in 2013