Arandaspis
Extinct genus of jawless fishes
title: "Arandaspis" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["pteraspidomorphi-genera", "ordovician-jawless-fish", "paleozoic-fish-of-australia", "early-ordovician-genus-first-appearances", "early-ordovician-genus-extinctions", "fossil-taxa-described-in-1977"] description: "Extinct genus of jawless fishes" topic_path: "geography/australia" source: "https://en.wikipedia.org/wiki/Arandaspis" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Extinct genus of jawless fishes ::
| fossil_range = Early Ordovician
| image = Arandaspis prionotolepis fossil.jpg | image_caption = Fossil of Arandaspis prionotolepis from Natural History Museum in London | taxon = Arandaspis | authority = Ritchie & Gilbert-Tomlinson, 1977 | type_species = †Arandaspis prionotolepis | type_species_authority = Ritchie & Gilbert-Tomlinson, 1977 | subdivision_ranks = Species | subdivision_ref = | subdivision =
- A. prionotolepis Ritchie & Gilbert-Tomlinson, 1977
- A. sp. Young, 1997
Arandaspis is an extinct genus of jawless fish that lived in the Ordovician period, about 480 to 470 million years ago. Its remains were found in the Stairway Sandstone near Alice Springs, Australia in 1959, but it was not determined that they were the oldest known vertebrates until the late 1960s. Arandaspis is named after a local Indigenous Australian people, the Aranda (now currently called Arrernte).
Description
::figure[src="https://upload.wikimedia.org/wikipedia/commons/5/55/Arandaspis_Wiki2.png" caption="Life restoration]], with trunk morphology based on speculation in Ritchie and Gilbert-Tomlinson (1977) and tail based on ''[[Sacabambaspis]]''"] ::
Arandaspis is estimated to reach around 12-14 cm long, with a body covered in rows of knobbly armoured scutes. The front of the body and the head were protected by hard plates with openings for the eyes, nostrils and gills. It probably was a filter-feeder. The morphology of its trunk and tail is unknown. According to comparisons with other early ostracoderms, it would have lacked paired fins and the caudal fin would be of a simple shape, although another arandaspid Sacabambaspis had a tail consisting of dorsal and ventral webs and an elongated notochordal lobe.
References
References
- "Pteraspidomorphi".
- Ritchie, Alexander. (1977). "First Ordovician vertebrates from the Southern Hemisphere". Alcheringa: An Australasian Journal of Palaeontology.
- Pradel, Alan. (2006-11-14). "The tail of the Ordovician fish ''Sacabambaspis''". Biology Letters.
::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::