Archaeoteleia Masner in the Cretaceous and a new species of Proteroscelio Brues ( Hymenoptera , Platygastroidea )

The generic concepts of Archaeoteleia Masner and Proteroscelio Brues are expanded to accommodate two new species that are here described: Archaeoteleia astropulvis Talamas sp. n. and Proteroscelio nexus Talamas sp. n. A specimen of Archaeoteleia from Baltic amber is illustrated and discussed. Diagnoses of Proteroscelio, Proterosceliopsis Ortega-Blanco, McKellar & Engel and Bruescelio Ortega-Blanco, McKellar & Engel, a key to Cretaceous platygastroid genera with 14-merous antennae, and a key to the species of Proteroscelio are presented.

Archaeoteleia Masner in the Cretaceous and a new species of Proteroscelio Brues (Hymenoptera, Platygastroidea)

Introduction
This work was catalyzed by two platygastroid specimens in Burmese amber brought to the National Museum of Natural History by Longfeng Li, a visiting student from Capitol Normal University, Beijing, during her study on fossil Hymenoptera.Both inclusions are exceptionally well preserved, and upon close examination, the specimens warrant expansion of the concepts of the genera to which they belong: Proteroscelio Brues and Archaeoteleia Masner.The former is only known from Cretaceous amber (Brues 1937, Johnson et al. 2008), while the latter has, until now, only been known from extant specimens in South America and New Zealand (Masner 1968, Early et al. 2007).
The generic placement of Archaeoteleia astropulvis Talamas exemplifies the importance of understanding the extant fauna of a taxon to interpret fossils.We place A. astropulvis in Archaeoteleia without reservation, but over the course of 100 million years, Archaeoteleia has changed enough that a novice might not recognize the characters that unite the fossil with extant species.This is particularly relevant because A. astropulvis does not fully comply with a generic concept of Archaeoteleia based solely on extant specimens (Early et al. 2007).Through examination of this specimen we discovered a new character that is found throughout Archaeoteleia, the form of the anterior mesepisternal area, which we use to reinforce the generic concept.Such union of fossil and extant morphologies is especially illuminating and requires examination of both kinds of specimens.
Proteroscelio nexus Talamas expands the range of morphological diversity found in Proteroscelio and reduces the number of characters that separate Proteroscelio from Bruescelio Ortega-Blanco, McKellar & Engel and Proterosceliopsis Ortega-Blanco, McKellar & Engel.As summarized in Talamas et al. (2015), dates of lineages are increasingly being utilized to understand the evolutionary history of groups with dating algorithms that rely on accurate taxonomy for proper calibration.Archaeoteleia astropulvis extends the age of Archaeoteleia ~100 million years into the past and confirms that it retains plesiomorphic characters, as was first posited by Masner (1968).

Materials and methods
The numbers prefixed with "USNMENT" or "OSUC " are unique identifiers for the individual specimens (note the blank space after some acronyms).The specimens in Burmese amber were given "USNMENT" collecting unit identifiers, and are also referenced by CNU collection numbers.Both identifiers are presented in the Material Examined sections.Details on the data associated with these specimens may be accessed at the following link: purl.oclc.org/NET/hymenoptera/hol,and entering the identifier in the form.Persistent URIs for each taxonomic concept were minted by xBio:D in accordance with best practices recommended by Hagedorn et al (2013).
Morphological terms were matched to concepts in the Hymenoptera Anatomy Ontology (Yoder et al 2010) using the text analyzer function.A table of morphological terms and URI links is provided in Suppl.material 1.
Taxonomic synopses and matrix-based descriptions were generated from the Hymenoptera Online Database (hol.osu.edu) and the online program vSysLab (vsyslab.osu.edu) in the format of character: state.
Photographs were captured with a Z16 Leica®™ lens with a JVC KY-F75U digital camera using Cartograph®™ software, or a Leica®™ DMRB compound microscope with a GT-Vision®™ Lw11057C-SCI digital camera attached.In both systems, lighting was achieved using techniques summarized in Buffington et al. (2005), Kerr et al. (2009) and Buffington and Gates (2009).Single montage images were produced from image stacks with the program CombineZP®™.In some cases, multiple montage images were stitched together in Photoshop®™ to produce larger images at high resolution and magnification.Full resolution images are archived at the image database at The Ohio State University (specimage.osu.edu).
Dissections for scanning electron microscopy were performed with a minuten probe and forceps and body parts were mounted to a 12 mm slotted aluminum mounting stub (EMS Cat.#75220) using a carbon adhesive tab (EMS Cat.#77825-12) and sputter coated with approximately 70 nm of gold/palladium using a Cressington®™ 108auto sputtercoater.Micrographs were captured using a Hitachi®™ TM3000

Concept of Archaeoteleia
To evaluate the morphology of extant Archaeoteleia we examined 14 species directly: (A.We place A. astropulvis in Archaeoteleia based on the presence of 2 tibial spurs on the metatibia, venation of the fore wing, the sulci along the anterior margins of T2-T4 and S2-S4, and the form of the anterior mesepisternal area.The distal apices of the mesotibiae are not clearly visible and although we did not observe them directly, we suspect that there are two mesotibial spurs as in all other Archaeoteleia. The following characters presented by Early et al. (2007) can no longer be treated as ubiquitous for Archaeoteleia: A3 the longest antennomere in females, episternal foveae absent, and the number of mandibular teeth (2 teeth in extant species, 3 in A. astropulvis).The characteristic shape of the clypeus in extant species was used by Early et al. (2007) as a generic character.The clypeus in the holotype specimen of A. astropulvis is obscured, precluding assessment of this character.However, based on the position of the interantennal process relative to the mandibles, we assume that the clypeus is much shorter than in extant species.
During the course of this study we encountered a male specimen in Baltic amber (Figures 15-18) that we tentatively identify as Archaeoteleia.The observable morphology is consistent with the concept of Archaeoteleia in Early et al. (2007), including the wing venation (Figure 17) and the presence of two tibial spurs on the hind tibia (Figure 16).Only the dorsal margin of the anterior mesepisternal area is clearly visible, and it is carinate (Figure 15) as in other macropterous specimens of Archaeoteleia.The metasoma is entirely occluded by a hole drilled through the amber and the ventral portion of the head is not visible.The description of Electroteleia Brues by Johnson et al. (2008) states that this genus has tyloids on the male antennomeres A4-A8.The specimen of Archaeoteleia illustrated in Figures 15-18 has a tyloid only on A5, consistent with the description of Archaeoteleia by Early et al. (2007).Despite the incompleteness of this specimen's visible morphology, we consider it useful to bring attention to it because other relevant specimens are likely present in Baltic amber collections and may shed light on the evolution of Archaeoteleia.

Antenna
Figure 3 (A.mellea) illustrates a distinctly elongate A3, which is typical for extant Archaeoteleia.However, even among extant species, this character exhibits significant variation.Figure 4 illustrates the head and antennae of a female of A. pygmea: A3 is the longest antennomere, but by a much smaller degree than in A. mellea and its length is of the same order of magnitude as A2.Because of this plasticity, we do not use relative antennomere length to exclude A. astropulvis, in which A3 is shorter than A2 and only slightly longer than A4, from Archaeoteleia.

Wing Venation
The degree to which the marginal vein is sclerotized differs significantly between A. astropulvis and from extant species and Archaeoteleia in Baltic amber 17).

Anterior mesepisternal area
In all species of Archaeoteleia, the anterior mesepisternal area is elevated relative to the surrounding mesopleuron and has carinate posterior margins.The posterodorsal margin of the anterior mesepisternal area corresponds with anterior limit of either the subacropleural sulcus or the prespecular sulcus.The posteroventral margin aligns with the episternal foveae (when foveae are present).We examined this character in representatives of more than 100 platygastroid genera across all subfamilies and major lineages and found that the anterior mesepisternal area is clearly delimited and present as a raised area in only a handful of genera outside of Archaeoteleia: Cremastobaeus Ashmead, Dyscritobaeus Perkins, Mecix Masner, Pseudanteris Fouts, Scelio Latreille, Synoditella Muesebeck, Telenomus Haliday and Thoron Haliday.In none of these are the posterior limits of the anterior mesepisternal area sharply margined by carinae as in Archaeoteleia.

Sexual dimorphism
The anterior mesepisternal area in the micropterous females of Archaeoteleia pygmea and apterous females of A. submetallica is a simple carina along the anterior margin of the mesopleuron (Figure 14).In the macropterous males of A. pygmea (Figure 11) the anterior mesepisternal area is fully developed in the form typical for the genus.The episternal foveae are an attachment site for the mesopleuro-mesobasalare muscle (Mikó et al. 2007), and thus it is unsurprising that microptery is associated with reduction in this character.The nature of the musculature, if any, associated with the subacropleural and prespecular sulci is presently unknown to us.We consider the form of the anterior mesepisternal area to be a generic character for Archaeoteleia, albeit one that is subsequently modified in micropterous or apterous females.

Pronotal shoulder
Some species of Archaeoteleia have two distinct sulci dorsal to the transverse pronotal carina.When both sulci are present, we refer to the sulcus along the dorsal margin of the pronotum as the pronotal suprahumeral sulcus, and the sulcus directly along the dorsal margin of the transverse pronotal carina as the postepomial sulcus.Diagnosis.Archaeoteleia astropulvis can be separated from females of extant species by multiple characters.A2 and A3 are distinctly elongate in extant species (Figures 3-4) and in A. astropulvis the length of these antennomeres is approximately equal to their width.The mandibles are bidentate in extant species and tridentate in A. astropulvis.Lastly, in extant macropterous species, the marginal vein is thickly sclerotized into a "stigma" whereas in A. astropulvis the marginal vein is simple.Etymology.This species epithet "astropulvis" is a Latin translation of "star dust", that refers to the ancient source of the atoms that form our planet and its inhabitants and commemorates the late David Bowie alter ego, Ziggy Stardust.It is treated as a noun in apposition.
Comments.Masner (1968) suggested that the evolutionary origin of Archaeoteleia might have been Antarctic in origin, consistent with the distribution of extant species and the absence of fossil evidence of Archaeoteleia from other regions.The discovery of A. astropulvis from Myanmar and the presence of Archaeoteleia in Baltic amber indicate that the distribution of the genus was once found much farther north.We posit that Archaeoteleia in South America and New Zealand represent relictual populations of a once expansive distribution.

Diagnosis of Proteroscelio
Proteroscelio can be identified by the following combination of characters: antennae 14-merous; clava in female antenna 8-merous and with pairs of basiconic sensilla arranged longitudinally; wings fully developed; 1Rs and M not intersecting in forewing.

Diagnosis of Proterosceliopsis
Proteroscelio nexus partially matches the diagnosis of Proterosceliopsis provided in Ortega-Blanco et al. ( 2014): 1Rs and M do not intersect, notauli are present and T1 is longitudinally striate.Their diagnosis stated that Proterosceliopsis has 6 visible tergites and a short, wide ovipositor.Based on the drawing and photograph of Proterosceliopsis masneri provided by Ortega-Blanco et al. (2014) (Figures 1, 6A) we offer an alternative interpretation, that the metasoma has 6 externally visible tergites and the apex is the partially extruded fusion of T7+8, as is found in scelionines with a Scelio-type ovipositor.In lieu of P. nexus, Proterosceliopsis can be differentiated from Proteroscelio by the fore wing not extending to the apex of the metasoma, a strongly transverse mesoscutellum and the presence of a horn on T1.  -Blanco et al. (2014) diagnosed Bruescelio on the basis of an antero-posteriorly compact shape of the head, a 6-merous clava, the absence of an occipital carina, 1Rs intersecting M in the fore wing.and T2 as the longest tergite.Proteroscelio nexus has T2 as the longest tergite (Figure 22), rendering this character unusable.The use of claval formula by Ortega-Blanco et al. (2014) for generic level diagnosis is potentially problematic because these authors did not clarify their criterion for differentiating between clavomeres and the funicle.In Proteroscelio antennalis and P. gravatus the size difference is sufficiently extreme that differentiating between clavomere and non-clavomere is straightforward.However, in P. nexus, the flagellomeres beyond A3 expand in size gradually , and thus explicit definition of clavomeres increases in importance.Proteroscelio antennalis and P. gravatus have compressed heads and P. nexus does not, obviating use of this character.Assuming that the clava in Bruescelio is 6-merous based on basiconic sensilla, Bruescelio can be separated from Proteroscelio by the following characters: clava 6-merous; occipital carina absent; 1Rs and M intersecting in the fore wing.

Character discussion
The monotypic Proterosceliopsis and Bruescelio were differentiated by Ortega-Blanco et al. (2014) from each other and from Proteroscelio based on characters that are commonly variable within extant genera: claval formula, sculpture of T1, presence of an occipital carina, head shape, length of wings, and the presence of a posterior scutellar sulcus (referred to as "posterior mesoscutellar pits.").We here provide perspective on some of these characters based on experience with a broad range of platygastroid genera.

Wing Venation
Ortega-Blanco et al. (2014) used the abbreviations 2Rs and 3Rs for abscissae of the radial sector vein (Rs) in the fore wing.However, none of the taxa treated by them exhibit three abscissae in Rs, and thus these should be treated as 1Rs and 2Rs respectively.Our naming convention for these veins follows that of Ross (1937), Goulet andHuber (1993), andDangerfiel et al. (2001).

Wing length
The length of the fore wing relative to the metasoma is often a consequence of metasomal length.Figures 24-25 and 26-27 illustrate two species of Triteleia Kieffer and two species of Trichoteleia Kieffer, respectively, in which the ratio of wing length to mesosomal length changes very little despite changes in the length of the metasoma.
The shape of the body in scelionids is thought to be influenced by the shape of the egg in which the parasitoid develops; species that develop in elongate eggs tend to have an elongate habitus and species that develop in globular eggs tend to have a compact habitus.Furthermore, several characters are allometrically linked to body size, which is a direct function of host size and quality (Buffington and Polaszek 2009).Dramatically different adult parasitoid morphologies, within a population, can result from development within hosts of varying size or quality.Consequently, the length of the wing relative to the metasoma is a highly plastic character that is indicative of ancestry only to the degree that host choice is.

Mesoscutal pits
This term is unknown to us.It is not found in the Hymenoptera Anatomy Ontology nor is it used in platygastroid literature known to us and we deduce that Ortega-Blanco et al. (2014) were referring to the posterior scutellar sulcus (Figure 22), which is indicated by cells in almost all Scelionidae.

Horn on T1
The presence of a horn on T1 is often highly variable within genera (e.g.Idris Förster, Inostemma Haliday, Probaryconus Kieffer), and even within a species (e.g.Trichoteleia janus Talamas).We consider its use as a generic character to be reasonable only when supported by congruence with other characters.

Metasomal sculpture
The value of metasomal sculpture as a generic character is an extreme rarity in Platygastroidea and we know of only one instance where metasomal sculpture has real diagnostic power at the generic level: T3 in Dvivarnus Rajmohana & Veenakumari.The presence of striation on T1 is of little use at the generic level because the vast majority of platygastroids have T1 longitudinally striate to some degree, and within a genus there may be closely related species that differ by this character.Diagnosis.Proteroscelio nexus is identifiable by the combination of strongly transverse T3-T5, percurrent notauli, and the serrate form of the clavomeres.

Proteroscelio nexus
Etymology.This species is given the name "nexus", derived from the Latin word for to "tie" or "bind" because this species shares characters between Proteroscelio and the previous concepts of Proterosceliopsis and Bruescelio, bringing these three genera closer together morphologically.