New Fossil Scorpion from the Chiapas Amber Lagerstätte

Abstract

A new species of scorpion is described based on a rare entire adult male preserved in a cloudy amber from Miocene rocks in the Chiapas Highlands, south of Mexico. The amber-bearing beds in Chiapas constitute a Conservation Lagerstätte with outstanding organic preservation inside plant resin. The new species is diagnosed as having putative characters that largely correspond with the genus Tityus Koch, 1836 (Scorpiones, Buthidae). Accordingly, it is now referred to as Tityus apozonalli sp. nov. Its previously unclear phylogenetic relationship among fossil taxa of the family Buthidae from both Dominican and Mexican amber is also examined herein. Preliminarily results indicate a basal condition of T. apozonalli regarding to Tityus geratus Santiago-Blay and Poinar, 1988, Tityus (Brazilotityus) hartkorni Lourenço, 2009, and Tityus azari Lourenço, 2013 from Dominican amber, as was Tityus (Brazilotityus) knodeli Lourenço, 2014 from Mexican amber. Its close relationships with extant Neotropic Tityus-like subclades such as ‘Tityus clathratus’ and the subgenus Tityus (Archaeotityus) are also discussed. This new taxon adds to the knowledge of New World scorpions from the Miocene that are rarely found trapped in amber.

A preliminary synopsis on amber scorpions with special reference to Burmite species: an extraordinary development of our knowledge in only 20 years

“…If this new fossil is considered as rare and outstanding by its authors, it should be noted that not only is Chiapas amber of recent Miocene age, some 20-15 Ma, but also that other species have been recently described from this same type of amber (Lourenço 2014), bringing as much, if not more, morphological information about these fossils. In the case of the species described by Riquelme et al (2015), some key morphological information such as the trichobothrial pattern is not clearly defined and in all cases not illustrated, attesting that the described specimen was likely not so unique. The major problem, however, with this publication is the fact that the authors rapidly diverge from the main goal, which should have been the thorough description of the new fossil scorpion, and instead proposed a type of global synopsis on scorpion fossils in amber, including comments on sedimentary fossils and even copal sub-fossils.…”

“…The exclusion of the family Archaeobuthidae from the buthoids has been proposed by a number of authors (Baptista et al 2006; Riquelme et al 2015), mainly on the basis of theoretical speculation. It is well known that both higher classification of scorpion in general and the classification of fossils in particular are controversial issues, which have been largely debated within scorpion taxonomy, especially during the last 20 years.…”

“…In a few cases only the originally described material has been re-examined, but in many other cases the critics were based solely on the originally published descriptions (see Riquelme et al 2015). In fact, when dealing with systematic studies of a given taxonomic group, it should be a standard practice to refer to and consider the available material cited in previous publications.…”

“…In a recent publication, eight authors have described a new fossil scorpion from Chiapas amber (Riquelme et al 2015). If this new fossil is considered as rare and outstanding by its authors, it should be noted that not only is Chiapas amber of recent Miocene age, some 20-15 Ma, but also that other species have been recently described from this same type of amber (Lourenço 2014), bringing as much, if not more, morphological information about these fossils.…”

“…The most critical mistake, however, is the proposition in a suggested cladogram (cf. figure 10 in Riquelme et al 2015) of the Burmite genus Palaeoburmesebuthus as incertae sedis , knowing that the familial status of this genus was already clarified several months before their publication (Lourenço 2015a). See systematic section for further discussion.…”