comment on this calibration


 node name
Acanthomorpha     Look for this name in NCBI   Wikipedia   Animal Diversity Web
  recommended citations Benton et al. 2015
  node minimum age
98 Ma
The Hajula Lagerstätte is located near the top of subdivision IVd according the local stratigraphic scheme applied to Cenomanian deposits in Lebanon (Hückel, 1970: fig. 3). Ammonites attributed to Mantilliceras mantelli are known from the overlying Cenomanian subdivision Va (Zummofen, 1926; Dalla Vecchia et al., 2002). M. mantelli defines the earliest complete ammonite zone of the Cenomanian. The top of the Mantelliceras mantelli Ammonite Zone can be dated as approximately 98.0 Ma (Gradstein et al., 2012), which we apply as our minimum age estimate for crown Acanthomorpha.
  node maximum age
158.3 Ma
Putative stem acanthomorphs like cthenothrissids and aulolepids (Rosen, 1973) first appear in the fossil record at approximately the same time as crown acanthomorphs. The earliest representatives of Myctophiformes, the living sister group of Acanthomorpha, also appear in the Cenomanian (Patterson, 1993b). High taxonomic richness of marine fishes in the Cenomanian has been interpreted as evidence of rapid diversification during the interval, but it is difficult to exclude the possibility that this pattern is an artifactual one arising from Lagerstätten effects (but see Cavin and Forey, 2007). The earliest acanthomorphs are relatively small-bodied, and there are comparatively few fully marine Early Cretaceous localities that preserve moderately diverse assemblages of euteleosts of this size. It is therefore plausible that crown acanthomorphs were present in the Early Cretaceous, but were not preserved. Indirect evidence supporting an older age for crown acanthomorphs comes from the composition of Cenomanian acanthomorph faunas, which include representatives of multiple extant lineages (e.g., Polymixiiformes, Beryciformes). We apply a conservative soft maximum bound on the age of the acanthomorph crown based on the numerous marine Lagerstätten of Late Jurassic (Kimmeridgian-Tithonian) age in Germany (Wattendorf, Nusplingen, Schamhaupten, Solnhofen, Mörnsheim) and France (Cerin, Canjeurs), none of which yield fossils attributable to Acanthomorpha or containing clades (Eurypterygii, Neoteleostei; Wiley and Johnson, 2010). The base of the Kimmeridgian is dated to 157.3 Ma ± 1.0 Myr. From this we derive a maximum age estimate of 158.3 Ma for the origin of crown Acanthomorpha.
 primary fossil used to date this node 
NHMUK P.47835
Stichocentrus liratus, Patterson, 1967
Location relative to the calibrated node: Crown

[show fossil details]
     Locality: Hajula
     Stratum: Sannine Limestone
     Geological age: Cretaceous, Mesozoic

More information in Fossilworks   PaleoBioDB

  phylogenetic justification
Cladistic analyses of early acanthomorphs have variously placed Stichocentrus as a stem holocentroid (Gayet, 1982) or a crown trachichthyoid (Otero et al., 1995). Although we remain agnostic with respect to its placement among Beryciformes, there is no doubt that Stichocentrus is a crown-group acanthomorph based on based on the presence of pelvic-fin spines in this genus. Pelvic-fin spines are classically regarded as a synapomorphy of Acanthopterygii inclusive of Zeiformes (e.g., Johnson and Patterson, 1993). However, molecular analyses strongly support placement of Zeiformes with Gadiformes outside Acanthopterygii (Wiley et al., 2000; Miya et al., 2003; Smith and Wheeler, 2006; Near et al., 2012). This arrangement implies that pelvic-fin spines either evolved independently in Zeiformes and Acanthopterygii, or been lost independently in some groups. However, this uncertainty does not affect our confidence in phylogenetic placement of Stichocentrus, because the origin of pelvic-fin spines is constrained to within crown Acanthomorpha under either scenario.
  phylogenetic reference(s)
Gayet, M. 1982. Essai de definition des relations phylogénetiques des Holocentroidea nov. et des Trachichthyoidea nov. (Pisces, Acanthopterygii, Béryciformes). Bulletin du Museum national d’Histoire naturelle, Paris, 4e sér., section C, 1-2:21-4
Otero, O., Dutour, Y. and Gayet, M. 1995. Hgulichthys, nouveau genre de Lissoberycinae (Trachichthyiformes, Trachichthyoidea) du Cénomanien inférieur marin de Hgula (Liban). Implications phylogénétiques. Geobios, Mémoire Spéciale, 28:711-717.
 tree image (click image for full size) 
tree image
Figure 6 of Benton et al. (2014).