Austrolimulidae

Austrolimulidae Temporal range: Kungurian–Hettangian PreꞒ Ꞓ O S D C P T J K Pg N
Fossils of Austrolimulus (top), Tasmaniolimulus patersoni (left), and Dubbolimulus (right)
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Order:	Xiphosura
Superfamily:	Limuloidea
Family:	† Austrolimulidae Riek, 1955

Austrolimulidae is an extinct family of xiphosurans belonging to the infraorder Limulina. Members of the family are known from the Permian to the beginning of the Jurassic, though one possible species has been reported from the end of the Cretaceous. Austrolimulids are known for amongst the most extreme morphologies among xiphosurans, including large elongated genal spines. Unlike living living horseshoe crabs (Limulidae), austrolimulids were likely adapted for freshwater and brackish environments. The large genal spines may have helped austrolimulids move in areas of unidirectional current, such as rivers. ^[1] They are considered to be the sister group to Limulidae. ^[2]

Genera

• † Austrolimulus Riek, 1955 Triassic, Beacon Hill Shale, NSW, Australia
• † Attenborolimulus Bicknell, 2021 Triassic (Olenekian), Petropavlovka Formation, Cis-Urals, Russia ^[3]
• † Batracholimulus Wilde, 1987 Triassic (Rhaetian), Exter Formation, Germany
• † Boeotiaspis Lamsdell, 2020 Carboniferous, United States (Jr. synonym) ^[2]
• †? Casterolimulus Holland, Erickson & O'Brien, 1975 Late Cretaceous (Maastrichtian) Fox Hills Formation, North Dakota, USA (Inconsistently placed in this family)
• † Dubbolimulus Pickett 1984 Middle Triassic (Anisian) Napperby Formation, Australia
• † Franconiolimulus Bicknell, Hecker & Heyng, 2021 ^[4] Early Jurassic (Hettangian) Bayreuth Formation  [ de ], Germany
• † Limulitella Schimper 1853 Middle Triassic (Anisian), Grés á Voltzia Formation, France
• † Panduralimulus Allen and Feldmann 2005 Early Permian (Kungurian), Lueders Formation, Texas, USA
• † Psammolimulus Lange 1923 Early-Middle Triassic, Solling Formation, Germany
• † Tasmaniolimulus Bicknell, 2019 ^[5] Early Triassic, ^[6] Jackey Shale, Tasmania, Australia
• † Vaderlimulus Lerner, Lucas and Lockley, 2017 ^[7] Early Triassic (Olenekian) Thaynes Group, Idaho, USA

References

1. Bicknell, Russell D. C.; Pates, Stephen (2020). "Pictorial Atlas of Fossil and Extant Horseshoe Crabs, With Focus on Xiphosurida". Frontiers in Earth Science. 8 98. Bibcode:2020FrEaS...8...98B. doi: 10.3389/feart.2020.00098 . ISSN   2296-6463.
2. Lamsdell, James C. (2020). "The phylogeny and systematics of Xiphosura". PeerJ. 8 e10431. doi: 10.7717/peerj.10431 . PMC   7720731 . PMID   33335810.
3. Bicknell, Russell D. C.; Shcherbakov, Dmitry E. (30 June 2021). "New austrolimulid from Russia supports role of Early Triassic horseshoe crabs as opportunistic taxa". PeerJ. 9 e11709. doi: 10.7717/peerj.11709 . ISSN   2167-8359. PMC   8254475 . PMID   34249518.
4. Bicknell, Russell D. C.; Hecker, Andreas; Heyng, Alexander M. (2021-02-11). "New horseshoe crab fossil from Germany demonstrates post-Triassic extinction of Austrolimulidae" . Geological Magazine. 158 (8): 1461–1471. Bibcode:2021GeoM..158.1461B. doi:10.1017/S0016756820001478. ISSN   0016-7568. S2CID   233937535.
5. Bicknell, Russell D. C. (2019-10-13). "Xiphosurid from the Upper Permian of Tasmania confirms Palaeozoic origin of Austrolimulidae". Palaeontologia Electronica. 22 (3): 1–13. doi: 10.26879/1005 . ISSN   1094-8074.
6. Bicknell, R. D. C.; Smith, P. M.; Brougham, T.; Bevitt, J. J. (2022). "An earliest Triassic age for Tasmaniolimulus and comments on synchrotron tomography of Gondwanan horseshoe crabs". PeerJ. 10 e13326. doi: 10.7717/peerj.13326 . PMC   9037155 . PMID   35480564.
7. Lerner, Allan J.; Lucas, Spencer G.; Lockley, Martin (2017-12-01). "First fossil horseshoe crab (Xiphosurida) from the Triassic of North America" . Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 286 (3): 289–302. Bibcode:2017NJGPA.286..289L. doi:10.1127/njgpa/2017/0702.