GONIASTERIDAE, Forbes, 1841

Mah, Christopher & Foltz, David, 2011, Molecular phylogeny of the Valvatacea (Asteroidea: Echinodermata), Zoological Journal of the Linnean Society 161 (4), pp. 769-788 : 778-779

THE GONIASTERIDAE

The Goniasteridae + four ophidiasterid genera are supported as monophyletic (node M in Fig. 1 ), consistent with historical definitions such as those outlined in A.M. Clark (1993) and Mah (2009). Several affinities between goniasterid genera are supported by our data, including between Calliaster and Milteliphaster , as suspected by Aziz & Jangoux (1985), and between Mediaster and Rosaster , as suggested by Fisher (1919).

Our data also support the monophyly of the coldwater corallivorous Hippasterinae as reviewed by Fisher (1911) and later by Mah et al. (2010). Fisher (1906) perceived affinities between Gilbertaster and the Hippasterinae, which were later confirmed by Mah et al. (2010). This subfamily originally included Hippasteria , Cryptopeltaster , and the distantly related Cladaster . Cladaster forms the sister group to the Hippasterinae in Figure 1 , which may or may not agree with the relationship hypothesized by Mah (2006) and Mah et al. (2010) depending on subsequent taxonomic sampling.

The most substantial difference from previous definitions in the Goniasteridae in Figure 1 is the inclusion of several goniasterid-like ophidiasterids, including Fromia + Celerina (which may be synonyms), and Neoferdina . This result supports a nonmonophyletic Ophidiasteridae and suggests that other unsampled goniasterid-like taxa, such as Dissogenes , Paraferdina , Ferdina , and Bunaster may also be correctly placed within the Goniasteridae . The particularly goniasterid-like appearance of Dissogenes has been discussed by Fisher (1919) and Jangoux (1981) as intermediate between ophidiasterids and goniasterids. Narcissia trigonaria is supported in an unusual position as the sister clade to the larger, diverse members of clade M, which removes it from both the historical Ophidiasteridae , as well as the ‘ophidiasterid-like goniasterid’ condition observed in Fromia and Neoferdina . However, the 100% bootstrap support for clade M, which includes Narcissia , strongly implies that it is not supported with the traditional Ophidiasteridae .

Our results show asterinids in a phylogenetic position that is similar to prior groupings established by morphological phylogenies. Blake (1987) showed asterinids, ganeriids, and poraniids as sister taxa to a large and diverse clade including goniasterids, ophidiasterids, and oreasterids, amongst others. Gale (1987b) included the asterinids (and ganeriids) as part of a polytomy with goniasterids and odontasterids. Aside from Pseudarchaster (which is discussed below) only one molecular phylogeny has included goniasterids in their taxonomic coverage. Knott & Wray (2000) included Mediaster , Hippasteria , and Ceramaster and although they were supported on a clade with other valvataceans, they did not cluster together.

Amongst modern Asteroidea, the Goniasteridae are perhaps the best observed in the fossil record, having a particularly rich diversity of fossil taxa in the Cretaceous of northern Europe (e.g. Breton, 1992). Jurassic Goniasteridae do occur (e.g. Breton, 1992) but several taxa are based on incomplete material and/or are similar to pseudarchasterines, which are supported with the Paxillosida in our treatment. Nymphaster , which occurs close to the basal dichotomy of the goniasterid lineage, occurs primarily in Cretaceous strata ( Gale, 1987a; Breton, 1992). Stemward amongst the Goniasteridae is Mediaster , which is represented by Mediaster hayi Blake 1986 from the Cretaceous of California. Other included genera with Cretaceous fossil occurrence include Hippasteria ( Fell, 1956) and Cladaster ( Medina & Del-Valle, 1983) .

Although Tosia was not explicitly dated, the pentagonasterine phylogeny presented by Mah (2007) suggested that phylogenetic events in the Tosia + Pentagonaster lineage were probably close to the Eocene/Oligocene climate shift associated with the isolation of Antarctica from Australia. This relatively younger Tosia + Pentagonaster lineage would be consistent with its relatively derived phylogenetic position and its relatively close relationship with the Antarctic Notioceramus . Molecular data supporting the presence of several goniasterid-like ophidiasterids amongst the Goniasteridae also shift the interpretation of goniasterid-like ophidiasterid fossils. Blake & Reid (1998) described two such taxa, Denebia and Altairia , from the Cretaceous of Texas.

Figures

Figure 1. Maximum likelihood tree of valvatacean sea stars rooted against forcipulatacean + velatid sea stars. The analysis is based on 1084 bp of concatenated sequence data from two mitochondrial rDNA genes and one nuclear protein-coding gene, early-stage histone H3. As discussed in the text, solasterids are treated as part of the ingroup. The analysis was carried out in RAxML with bootstrap percentages indicated for nodes that had> 50% support. Boxed letters A–P are referred to in the text. Traditional family names are shown at the right; all families are in the Valvatida except as noted. The scale bar shows the expected number of substitutions.