THAUMASTELLIDAE Seidenstücker Historical

Grazia, Jocelia, Schuh, Randall T. & Wheeler, Ward C., 2008, Phylogenetic relationships of family groups in Pentatomoidea based on morphology and DNA sequences (Insecta: Heteroptera), Cladistics 24, pp. 932-976 : 966-967

publication ID

https://doi.org/ 10.1111/j.1096-0031.2008.00224.x

DOI

https://doi.org/10.5281/zenodo.4334458

persistent identifier

https://treatment.plazi.org/id/03E187AB-6B77-FFF2-FCFD-F99313564915

treatment provided by

Valdenar

scientific name

THAUMASTELLIDAE Seidenstücker Historical
status

 

THAUMASTELLIDAE Seidenstücker Historical : The superfamilial position of this family group has been controversial since the time of its description. Having been originally placed in the Lyg-

aeoidea, the Thaumastellidae was transferred to the Pentatomoidea at family rank by Štys (1964a) and later reduced to a subfamily of the Cydnidae by Dolling (1981) and Jacobs (1989). Jacobs (1989) mentioned the presence of a microchromosome (m-chromosome) in the Thaumastellidae , which is also present in many Coreoidea, Lygaeoidea, and Pyrrhocoroidea ( Largidae ). Henry

(1997) suggested that the m-chromosome is a synapomorphy defining this broad group within the Pentatomomorpha , albeit lost in a few taxa ( Berytidae , Lygaeinae , and Piesmatidae ), and that the Thaumastellidae , due to

the presence of an m-chromosome, may therefore not belong in the Pentatomoidea . Nonetheless, many apomorphies of the Pentatomoidea are found in the Thaumastellidae , including the presence of the foretibial apparatus, expanded mandibular plates, the base of the head not forming a ‘‘neck’’, post-ocular tubercles absent, the structure of the female genitalia, and the paired lateral trichobothria.

Analytical result: Because of the controversy over placement of the Thaumastellidae , and their rarity in collections, we felt fortunate to be able to secure sequences of two species of Thaumastella Horváth, offering new evidence to test the relationships of the taxon. In our morphological analyses ( Figs 42–44 View Fig View Fig View Fig ) the Thaumastellidae is placed within the Cydnidae , in conformity with the theory proposed by Dolling (1981), an unsurprising result. The strict consensus of molecular data with a 1: 1 cost ratio places the Thaumastellidae as the sister group of the Pentatomidae ( Fig. 45 View Figs 45–48. 45 ); changing the cost ratio to 2: 2 places Thaumastella in a clade that includes the Urostylididae , Dinidoridae , Tessaratomidae , Canopus , and Phloea ( Fig. 46 View Figs 45–48. 45 ). These results are more or less duplicated in the 52-taxon combined analyses ( Figs 51 and 52 View Figs 49–52. 49 ), although there Thaumastella becomes the sister group of the Acanthosomatidae + Lestoniidae under a 1: 1 cost ratio ( Fig. 51 View Figs 49–52. 49 ), rather than of the Pentatomidae . The 92-taxon combined analyses always place the Thaumastellidae in a clade containing most of the other ‘‘cydnoid’’ taxa ( Figs 53–55 View Fig View Fig View Fig ). Although it seems abundantly clear that Thaumastella belongs within the Pentatomoidea , as opposed to the Lygaeoidea, because it never falls outside the ingroup in any of our analyses, we continue to maintain it at the family level, in the absence of a more clear-cut signal regarding the details of its phylogenetic placement within the group, and more particularly a more rigorous test of the monophyly of the Cydnidae sensu Dolling. Morphological features treated as diagnostic for the Thaumastellidae in our analyses are the short scutellum that at most barely surpasses the posterior margin of the metathorax (160) and the claval commissure reduced, being no more than half the length of the scutellum (171).