Halecomorphi Explained

Halecomorphi is a taxon of ray-finned bony fish in the clade Neopterygii. The only extant Halecomorph species are the bowfin (Amia calva) and eyespot bowfin (Amia ocellicauda), but the group contains many extinct species in several families (including Amiidae, Caturidae, Liodesmidae, Sinamiidae) in the order Amiiformes, as well as the extinct orders Ionoscopiformes, Panxianichthyiformes, and Parasemionotiformes. The fossil record of halecomorphs goes back at least to the Early Triassic epoch.

The Halecomorphi exhibit a combination of ancestral features, such as most heavily mineralized scales, but also by more derived or "modern" features, particularly in the structure of the skull (e.g. position and shape of preopercles). Unique derived traits (synapomorphies) of the Halecomorphi include:[1]

Systematics and phylogeny

On the systematic position of the Halecomorphi, there are two competing hypotheses:

The latter hypothesis is more widely accepted.[6] [7] [8]

The following cladogram[9] summarizes the evolutionary relationships of extinct (indicated with a dagger, †) and living orders of Halecomorphi.

References

Notes and References

  1. Book: Ax, Peter [translated by Dr.Richard. E. Dunmur]. 2003 . Multicellular Animals. Gardners Books. Berlin. 978-3-642-05515-7. 207–210. 10.1007/978-3-662-08874-6_29. Halecomorphi — Teleostei.
  2. Patterson C. Interrelationships of holosteans. In: Greenwood P H, Miles R S, Patterson C, eds. Interrelationships of Fishes. Zool J Linn Soc, 1973, 53(Suppl): 233–305
  3. Olsen P. E.. The skull and pectoral girdle of the parasemionotid fish Watsonulus eugnathoides from the Early Triassic Sakemena Group of Madagascar with comments on the relationships of the holostean fishes. J Vertebr Paleontol. 1984. 4. 3. 481–499. 10.1080/02724634.1984.10012024. 1984JVPal...4..481O. 10.1.1.384.2050.
  4. Grande. Lance. Bemis, William E.. A Comprehensive Phylogenetic Study of Amiid Fishes (Amiidae) Based on Comparative Skeletal Anatomy. an Empirical Search for Interconnected Patterns of Natural History. Journal of Vertebrate Paleontology . 1998 . 18 . sup001 . 1–696 . 10.1080/02724634.1998.10011114. 1998JVPal..18S...1G .
  5. López-Arbarello . Adriana . Sferco . Emilia . Neopterygian phylogeny: the merger assay. . Royal Society Open Science . March 2018 . 5 . 3 . 172337 . 10.1098/rsos.172337. 29657820 . 5882744 . 2018RSOS....572337L . free .
  6. Web site: Betancur-R . Phylogenetic Classification of Bony Fishes Version 4 . 2016 . 2021-06-06 . 2017-07-11 . https://web.archive.org/web/20170711171156/https://sites.google.com/site/guilleorti/classification-v-4 . dead .
  7. Book: Nelson, Joseph, S.. Fishes of the World. 2016. John Wiley & Sons, Inc. 978-1-118-34233-6 .
  8. Web site: R. Froese and D. Pauly. FishBase . February 2006.
  9. Sun . Zuoyu . Tintori . Andrea . Xu . Yaozhong . Lombardo . Cristina . Ni . Peigang . Jiang . Dayoung . A new non-parasemionotiform order of the Halecomorphi (Neopterygii, Actinopterygii) from the Middle Triassic of Tethys. . Journal of Systematic Palaeontology . April 2017 . 15 . 3 . 223–240 . 10.1080/14772019.2016.1181679. 2017JSPal..15..223Z . 133176227 .