compiled by A. Lopez-Arbarello & G. Arratia
Which is the sister group of Teleostei?
- Teleostei, with about 27,000 extant species is the largest group among actinopterygians (Nelson 2006). Teleosts have a long evolutionary history that can be traced back to the Late Triassic if Pholidophorus is included at the basal position or to the Early Jurassic if Leptolepis coryphaenoides (a “true” teleost) is considered the basal taxon (Arratia 1996, 1997, 2001). Although the monophyly of Teleostei is unquestioned (Pinna 1996, Arratia 1999), there are many open questions concerning the content of the group, its basal forms, and potential stem-group teleosts.
The sister-group relationship of teleosts is still controversial (Arratia 2001, 2004b). Candidates are the amiids (Patterson 1973), lepisosteids (Olsen 1984), the Halecomorphi (Grande & Bemis 1998), †Dapedium (Gardiner et al. 1996), pycnodontiforms (Nursall 1996), pachycormiforms (Patterson 1977), and aspidorhynchiforms (Patterson 1977, Maisey 1991, Brito 1997). However, their relative positions in the cladogram change when different outgroups are used (Arratia 1999).
Molecular studies have not clarified the question. For instance, the clade Amia + Lepisosteus as the sister group (Normark et al. 1991, Lê et al. 1993) or the clade Acipenseriformes + Lepisosteidae + Amiidae as the sister group (Inoue et al. 2003).
- Cladogram (opens in new window)
- Cladogram (download as pdf; 260kb)
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