Blochius

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Blochius
Temporal range: Early Eocene
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Blochius longirostris 3434.JPG
Blochius longirostris
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Carangiformes
Suborder: Menoidei
Superfamily: Xiphioidea
Family: Blochiidae
Bleeker, 1859
Genus: Blochius
Volta, 1800
Species
  • B. longirostris
  • B. macropterus
  • B. moorheadi

Blochius is an extinct genus of billfish from the Eocene. It is only known from the Monte Bolca deposits in Italy, and was likely restricted to shallow, tropical waters of the Tethys Ocean. [1] [2]

Contents

Discovery

The existence of Blochius was known as early as 1709, where it is mentioned in a written account by Johann Jakob Scheuchzer, who identified a fragment of a Blochius skeleton and identified it as being either related to the Xiphias (swordfish) or Siluro (catfish). It was not until the advent of Linnean taxonomy that it properly received a scientific name by Giovanni Serafino Volta, who named Blochius in 1796 after pioneering ichthyologist Marcus Elieser Bloch. [3]

Taxonomy

It is one of two known definite genera in the family Blochiidae, alongside Loancorhynchus from earlier in the Eocene of Chile. [4] The indeterminate remains of a Blochius-like fish are known from the Late Paleocene of Peru. [5] Indeterminate blochiid remains are also known from the middle Eocene of Uzbekistan, and from the latest Paleocene/earliest Eocene Danata Formation of Turkmenistan. [6] [7] Other potential blochiids such as Acestrus , Aglyptorhynchus , Hemirhabdorhynchus , Cylindracanthus and Congorhynchus are based on highly fragmentary remains and it is thus uncertain if they are blochiids, or even billfish for the last two. [2] [8] [3] Some authorities have found the Blochiidae to be basal billfish not closely related to any extant groups, whereas others find them to be more closely related to swordfish (Xiphiidae) than to marlins & sailfish (Istiophoridae). [9]

Life restoration FMIB 52200 Blochius longirostris Volta, restored Upper Eocene of Monte Bolca.jpeg
Life restoration

The following species are known, all from Italy:

Description

With prey Blochius longirostris with prey.jpg
With prey

Blochius had a very slender elongated body, a narrow head with elongated upper and lower jaws and large eyes. Much like its modern relatives such as swordfish, it had an elongated rostrum. [2] [10] Although generally small in size at around 2 feet in length, it could reach a maximum length of 2.155 metres (7.07 ft). The rostrum generally comprised 40% of the body length. [3] [11] It likely hunted in a manner similar to modern needlefish. [3] [11]

Bibliography

References

  1. "PBDB". Paleobiology Database . Retrieved 2024-03-19.
  2. 1 2 3 Fierstine, Harry L. (2006-11-01). "Fossil history of billfishes (Xiphioidei)". Bulletin of Marine Science. 79 (3): 433–453.
  3. 1 2 3 4 Fierstine, Harry L.; Monsch, Kenneth A. (2002). "Redescription and phylogenetic relationships of the family Blochiidae (Perciformes: Scombroidei), Middle Eocene, Monte Bolca, Italy". Studie Ricerchesui Giacimenti Terziari di Bolca, Museo Civico di Storia Naturale di Verona. 9: 121–163.
  4. Otero, Rodrigo A. (2019). "Loancorhynchus catrillancai gen. et sp. nov., a new swordfish (Xiphioidei, Blochiidae) from the Middle Eocene of central Chile". PeerJ. 7: e6671. doi: 10.7717/peerj.6671 . ISSN   2167-8359. PMC   6440463 . PMID   30941278.
  5. Friedman, Matt; V. Andrews, James; Saad, Hadeel; El-Sayed, Sanaa (2023-06-16). "The Cretaceous–Paleogene transition in spiny-rayed fishes: surveying "Patterson's Gap" in the acanthomorph skeletal record André Dumont medalist lecture 2018". Geologica Belgica. doi: 10.20341/gb.2023.002 . ISSN   1374-8505.
  6. "PBDB". Paleobiology Database . Retrieved 2024-03-19.
  7. Monsch, Kenneth A.; Bannikov, Alexandre F. (2011). "New taxonomic synopses and revision of the scombroid fishes (Scombroidei, Perciformes), including billfishes, from the Cenozoic of territories of the former USSR" . Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 102 (4): 253–300. Bibcode:2011EESTR.102..253M. doi:10.1017/S1755691011010085. ISSN   1755-6910. S2CID   129577132.
  8. Parris, D. C., Grandstaff, B. S. and Bell, G. L. 2001. Reassessment of the affinities of the extinct genus Cylindracanthus (Osteichthyes). Proceedings of the South Dakota Academy of Science, 80: 161–172.
  9. Near, Thomas J; Thacker, Christine E (18 April 2024). "Phylogenetic classification of living and fossil ray-finned fishes (Actinopterygii)". Bulletin of the Peabody Museum of Natural History. 65. doi: 10.3374/014.065.0101 .
  10. De Gracia, Carlos; Correa-Metrio, Alex; Carvalho, Mónica; Velez-Juarbe, Jorge; Přikryl, Tomáš; Jaramillo, Carlos; Kriwet, Jürgen (2022-12-31). "Towards a unifying systematic scheme of fossil and living billfishes (Teleostei, Istiophoridae)" . Journal of Systematic Palaeontology. 20 (1): 1–36. Bibcode:2022JSPal..20....1D. doi: 10.1080/14772019.2022.2091959 . ISSN   1477-2019.
  11. 1 2 Ellis, Richard (2013). Swordfish. University of Chicago Press. doi:10.7208/chicago/9780226922928.001.0001. ISBN   978-0-226-92290-4.