NOVITATES CARIBAEA 15: 1–8, 2020
NEW GENUS AND FIRST RECORD OF HYBOTINAE
(DIPTERA: EMPIDOIDEA: HYBOTIDAE) IN MIDDLE MIOCENE
Nuevo género y primer registro de Hybotinae (Diptera: Empidoidea: Hybotidae)
en ámbar dominicano del Mioceno medio
Mónica M. Solórzano-Kraemer1*, Xavier Delclòs2, Enrique Peñalver3, and Bradley J. Sinclair4
1Senckenberg Research Institute, 60325 Frankfurt am Main, Germany; *Para correspondencia: monica.solorzano-
email@example.com; orcid.org/0000-0003-3065-119X. 2Dept. Dinàmica de la Terra i de l’Oceà,
Facultat de Ciències de la Terra, and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona,
08028 Barcelona, Spain; firstname.lastname@example.org; orcid.org/0000-0002-2233-5480. 3Instituto Geológico y Minero
de España (Museo Geominero), 46004 Valencia, Spain; email@example.com; orcid.org/0000-0001-8312-6087.
4Canadian National Collection of Insects & Canadian Food Inspection Agency, OPL-Entomology, K.W. Neatby
Bldg., C.E.F., 960 Carling Ave., Ottawa, ON, K1A 0C6, Canada; firstname.lastname@example.org.
A new fossil genus of the family Hybotidae is described, based on male and female
specimens. The new genus is monotypic: Syneproctus caridadi gen. et sp. nov. It belongs
to the subfamily Hybotinae and shares some characters with the extant genera Syneches
Walker, 1852, Stenoproctus Loew, 1858 and Chillcottomyia Saigusa, 1986; however,
the dierences, principally in the wing venation (shortened cua cell, horizontal m-cu crossvein)
and sclerotized mouthparts, support the description of a new genus. This is the rst description
of a new taxon of the subfamily Hybotinae from specimens preserved in Dominican amber.
Keywords: Dominican amber, new genus and species, Syneches, Stenoproctus, Chillcottomyia.
Se describe un nuevo género de la familia Hybotidae, basado en especímenes de ambos sexos.
El nuevo género comprende una única especie: Syneproctus caridadi gen. et sp. nov. Pertenece a
la subfamilia Hybotinae y comparte algunos caracteres con los géneros actuales Syneches Walker,
1852, Chillcottomyia Saigusa, 1986 y Stenoproctus Loew, 1858; sin embargo, las diferencias,
principalmente en la venación alar (celda cua corta, vena transversa m-cu horizontal), y aparato
bucal esclerotizado respaldan la descripción de un nuevo género. Esta es la primera descripción
de un nuevo taxon de la subfamilia Hybotinae a partir de especímenes preservados en
Palabras clave: ámbar dominicano, nuevo género y especie, Syneches, Stenoproctus, Chillcottomyia.
Empidoid ies are abundant in amber, copal, resin and are readily trapped in eld
actuotaphonomic research using sticky traps (Solórzano-Kraemer et al., 2018). Individuals of
the family Hybotidae are relatively common in amber, principally in Cretaceous and Eocene
ambers with species described from Spanish, Burmese and Baltic ambers (Penney, 2010).
From Miocene amber only the subfamily Tachydromiinae (Diptera, Empidoidea, Hybotidae)
has been reported in Mexican and Dominican ambers (Solórzano-Kraemer et al., 2005).
2NOVITATES CARIBAEA, núm. 15, 2020
The new genus is embedded in Dominican amber, which originated from Miocene
(20 to 15 my) resin (Iturralde-Vinent & MacPhee, 1996; Iturralde-Vinent, 2001; Iturralde-Vinent
& MacPhee, 2019). The plant source of the fossil resin is considered to be a representative of
the genus Hymenaea Linnaeus, 1753, the fossil species Hymenaea protera Poinar, 1991, which
is closely related to extant H. verrucosa Gaertner, 1791, from east Africa and Madagascar.
The new genus herein described belongs to the subfamily Hybotinae on the basis of
the holoptic female, stout and obliquely projecting proboscis, wing broad with two veins
emitted from wing cell dm and prosternum isolated and separated from the proepisternum
(Sinclair & Cumming, 2006). The subfamily Hybotinae is today known from the Dominican
Republic with three genera recorded: Euhybus Coquillett, 1895, Neohybus Ale-Rocha &
Carvallo, 2003 and Syneches Walker, 1852. Neohybus is restricted to Neotropical Americas
(Ale-Rocha & Rafael, 2004), whereas Euhybus has been recorded beyond the New World,
but the denition of the genus needs to be re-examined (Sinclair & Cumming, 2017).
Syneches is cosmopolitan in distribution and broadly dispersed with approximately 189 species
described (Menezes & Ale-Rocha, 2016). Most species of Syneches occur in tropical regions.
In America, the genus is widespread from southern Canada, to the south of Brazil and the Antilles
(Wilder, 1974; Menezes & Ale-Rocha, 2016). The Hybotinae are predaceous ies living
in various forest habitats, with adults capturing prey during ight (Sinclair & Cumming, 2017).
- To increase the knowledge of the Caribbean paleoentomofauna based on the study of
new and uncommon insect specimens preserved in Miocene Dominican amber, as is the
case of the first description herein of a new fossil taxon of the subfamily Hybotinae from
MATERIALS AND METHODS
The pieces of amber with the three specimens described herein (Fig. 1) were acquired
from private collections, and at least one amber piece (MNHNSD FOS 17.01) was collected in
La Toca mine belonging to La Toca Formation, dated as early middle Miocene
(Iturralde-Vinent & MacPhee, 1996). The other piece, having two y specimens,
originates from the Dominican Republic, from La Toca Formation but of unknown mine
(SFM Be 12428). The specimens are preserved in two pieces of yellow–red amber with
some impurities and one of them contains syninclusions. The pieces were cut, polished and
embedded in Araldit 2020 to avoid future oxidation. The specimens were examined under a
Nikon SMZ1000 stereomicroscope. Photographs were taken using a digital camera attached
to a Nikon SMZ25 microscope. Drawings were made using a camera lucida attached to the
Nikon SMZ1000 stereomicroscope.
The terminology follows Cumming and Wood (2017). Abbreviations of morphological
features: ad = anterodorsal; av = anteroventral setae; bm = basal medial cell; br = basal
radial cell; cerc = cercus; CuA = anterior branch of cubital vein; cua = anterior cubital cell;
CuA+CuP = anterior branch of cubital vein + posterior branch of cubital vein; d = dorsal
bristles; dc = dorsocentral bristles; dm = discal medial cell; epand = epandrium; h = humeral
crossvein; hypd = hypandrium; M1, M4 = medial veins; m-cu = medial-cubital crossvein;
pd = posterodorsal; pv = posteroventral; R1, R2+3 = radial veins; Rs = radial sector; Sc = subcostal
vein; st = sternite; sur = surstylus; tg = tergite; v = ventral setae.
SOLÓRZANO-KRAEMER et al.: Hybotinae in middle Miocene Dominican amber
One of the amber pieces (Fig. 1C) was donated by Jorge Caridad to the Museo Nacional
de Historia Natural “Prof. Eugenio de Jesús Marcano”, Santo Domingo, Dominican Republic
(labelled MNHNSD FOS 17.01).
The electronic version of this article in Portable Document Format (PDF) will represent a
published work according to the International Commission on Zoological Nomenclature (ICZN),
and hence the new name contained in the electronic version is eectively published under that
Code from the electronic edition alone. This published work and the nomenclatural act it contains
have been registered in ZooBank, the online registration system for the ICZN. The ZooBank
LSIDs (Life Science Identiers) can be resolved and the associated information viewed through
any standard web browser by appending the LSID to the prex “http://zoobank.org/”. The LSID for
this publication is: urn: lsid:zoobank.org:pub: A143E982-0C6B-4B89-B157-ACAD969D3457.
Order Diptera Linnaeus, 1758
Family Hybotidae Meigen, 1820
Syneproctus gen. nov.
Type species: Syneproctus caridadi sp. nov., here designated. Monotypic genus.
Etymology. The name Syneproctus is a combination of Syneches and Stenoproctus Loew.
The gender is masculine.
Diagnosis. Head hemispherical and holoptic in both sexes, eyes bare, frontally attened and
inated, making the head wider than its height (from anterior view); postpedicel tapered
with apical arista-like stylus; mouthparts stoutly sclerotized and slender, narrow and apically
pointed, without pseudotracheae; palpus slender, much shorter than labrum with long apical
setae; thorax highly arched; hind femur enlarged and spinose beneath; wings broad, with
distinct pterostigma; Rs elongate, arising in proximal half of cell br; m-cu crossvein horizontally
orientated; vein CuA+CuP not reaching the wing margin; cell cua shorter than cell bm;
CuA slightly arched; cell dm enlarged, longer and broader than basal cells; male terminalia
nearly symmetrical, lacking articulated surstyli, rotated 45° to the right.
Syneproctus caridadi sp. nov.
LSID urn:lsid:zoobank.org: pub: A143E982-0C6B-4B89-B157-ACAD969D3457.
Diagnosis. Pterostigma more than 3 times as long as wide, lling apical 0.3 of cell r1.Veins R4+5
and M1 not distinctly convergent apically. Hind femur swollen and bearing spine-like ventral
setae mounted on short protuberances, the rst seven on nger-like ventral tubercles, the other
11 on short elevations.
Diagnosis. Pterostigma 3 veces más largo que ancho, llenando apicalmente 0.3 de la celda
r1. Venas R4 + 5 y M1 no claramente convergentes apicalmente. Fémur posterior hinchado y con
setas ventrales emergiendo de protuberancias cortas, las primeras siete de tubérculos ventrales
en forma de dedos, las otras once de elevaciones cortas.
4NOVITATES CARIBAEA, núm. 15, 2020
Holotype (male). DOMINICAN REPUBLIC. SMF Be 12428a and Allotype (female)
SMF Be 12428b. Housed at Senckenberg Forschungsinstitut und Naturmuseum
(Frankfurt, Germany). The holotype and allotype are present in the same amber piece,
close together and in the same resin (amber) ow (layer) indicating spatial and temporal
co-occurrence. Syninclusions: one Hymenoptera covered with micro bubbles, one male of
Diptera: Psychodidae: Trichomyiinae, one male of Diptera: Chironomidae, and one Acari.
Paratype (female). DOMINICAN REPUBLIC. MNHNSD FOS 17.01. Housed at Museo Nacional
de Historia Natural “Prof. Eugenio de Jesús Marcano”. Without associated syninclusions.
Holotype (male). Body length 4.25 mm. Head: Eyes attened dorsally and upper facets enlarged.
Ocellar triangle elevated, bare and shiny; bearing 2 long ocellar bristles; postocular setae short
and proclinate. Antenna placed at middle of head; scape and pedicel subcylindrical; pedicel
larger than scape, with distal ring of setae; postpedicel pointed, bilaterally symmetrical,
elongate, basally swollen, 0.15 mm length, 0.07 mm width; arista-like stylus terminal, 0.7 mm
length, 2-articulated, basal article very short (Fig. 2C). Proboscis shorter than head. Palpus
with 3 apical setae, second seta shorter and apical seta as long as palpus. Thorax: Scutum,
scutellum and pleura shiny with some ne microsetae. Pronotum long with 1 strong marginal
seta and 2 slender setae. Scutum rounded dorsally, greatly convex, with sparse slender
setae; setae of prescutellar disc long and strong; acrostichal setulae and dorsocentral setulae
uniserial; 1 supra-alar seta strong; scutum with pattern of color showing 4 black lines. One pair
of apical scutellar spine-like bristles and 3 weak lateral bristles, two about 1/4 length of apical
pair and one in middle of two small ones about ½ length of apical pair. Legs clothed in slender
and long setae, denser in tarsomeres. Fore femur slightly wider than mid femur. Fore tibia darker
than mid and hind tibiae. Hind tibia geniculate at base. Outstanding bristles: Fore tibia with
2 av, 1 ad, 3 pv and 1 pd not reaching apex of corresponding tarsomere 1. Fore tarsomere
1 with 1 long, posterior, robust preapical seta not extending beyond apex of fore tarsomere 2.
Mid tibia with 2 long robust av, 2 ad, 2 pv and 1 pd. Mid tarsomere 1 with 1 long posteroventral
bristle near base, almost reaching base of tarsomere 2. Hind tibia with long simple setae and
row of 18 v shorter tuberculated spines. Hind tarsomere without spines, with dense short
setae. Pulvilli all of same length. Hind femur thickened, 4.6 times as long as wide; with one
seta at apical quarter, 1 ad near apex; row of 7 av long spines; row of 18 v shorter tuberculated
spines, tubercles more conspicuous on distal half. Wing (Fig. 2A): 3.8 mm length. Pterostigma
more than 3 times as long as wide, light brown, lling apical 0.3 of cell r1. Sc running very close
to R1 and fading away. R4+5 and M1 not distinctly convergent apically. Cell dm large with short
M4. Abdomen: broad, apparently attened dorsoventrally. All tergites with long setae. Segment
8 rotated 45°. Terminalia: Epandrium with medially directed subapical pointed process
(Fig. 2D); apex of epandrium (surstylus) tapered, medially directed with slender, pointed
tooth-like apex. Hypandrium distinctly longer than wide, narrowed towards tip. Phallus dicult
to observe but seems thin and acute (Fig. 2B).
Paratype (female). Similar to male. Body length 4.76 mm. Legs: Hind trochanter with
2 robust posteroventral distal bristles. Hind femur as thickened as in male, 4.6 times as long
as wide with 1 d seta at apical quarter, 1 ad near apex; row of 9 av long spines, basal seta
shorter and not as strong as other 8 av; row of 18 v shorter tuberculated spines (Fig. 2E).
Terminalia: as in Fig. 2F.
Etymology. The species name caridadi is a dedication to the Dominican family Caridad, owners
of the World Amber Museum in Santo Domingo.
SOLÓRZANO-KRAEMER et al.: Hybotinae in middle Miocene Dominican amber
Remarks. To nd male and female specimens of the same species is rather uncommon in the fossil
record. In the amber piece SMF Be 12428, the male (Holotype), (Fig. 1, A, B and D), and female
(Allotype; Fig. 1, A, E) are preserved together. They appear head to head, not in copula position
but originally in the same resin layer. Present in this amber piece there are other syninclusions;
however, these were trapped at dierent times, thus in dierent resin layers. We consider the
exemplars conspecic because they share all the relevant morphological characters and only
the few dierences they show could be considered of sexual dimorphism. We choose to describe
the paratype female and not the allotype because of the favorable position of the specimen in the
piece of amber that allow much better visibility and presentation of the characters. However, all
the relevant characters have been observed in both specimens.
Figure 1. Photographs of Syneproctus caridadi gen. et sp. nov. (Empidoidea, Hybotidae). A, SMF Be 12428, general view
of the amber piece with the holotype (♂; right) and the allotype (♀; left) very close to each other. B and D, holotype (♂)
SMF Be 12428a, habitus in dierent views. C, paratype (♀) MNHNSD FOS 17.01, habitus. E, allotype (♀) SMF Be 12428b
habitus. Scale bars = 0.5 mm.
6NOVITATES CARIBAEA, núm. 15, 2020
Figure 2. Camera lucida drawings of the major anatomical features of Syneproctus caridadi gen. et sp. nov. (Empidoidea, Hybotidae).
A–D, holotype (♂) SMF Be 12428a. A, wing. B, terminalia in dorsal view. C, antennae. D, terminalia in ventral view. E–F, paratype
(♀) MNHNSD FOS 17.01. E, detail of the hind leg. F, terminalia in ventral view. Scale bars = 0.5 mm.
SOLÓRZANO-KRAEMER et al.: Hybotinae in middle Miocene Dominican amber
In the key to genera of Neotropical Hybotinae by Ale-Rocha and Carvalho (2003),
the new genus runs to Syneches. Syneproctus gen. nov. is distinguished from Syneches
by the more tapered postpedicel, horizontally orientated crossvein m-cu and cell cua much
shorter than cell bm. In Syneches, the postpedicel is apically oval, m-cu is obliquely positioned
and cell cua is long, extending beyond cell bm. The wing venation of the new genus is more
like that of the Afrotropical genus Stenoproctus Loew, 1858. The nearly horizontally orientated
crossvein m-cu creates a straight line connection between cells bm and dm, and the shortened
cell cua is somewhat similar to Stenoproctus (see Sinclair & Cumming, 2017, g. 20). But
unlike Stenoproctus, with its more membranous proboscis and presence of pseudotracheae, the
proboscis of Syneproctus gen. nov. is stout and heavily sclerotized and Syneches-like. Species
of the new genus were probably predaceous on the basis of the piercing like proboscis shared
with other genera of Hybotinae. The new genus is also very similar to Chillcottomyia Saigusa,
1986, known from the Afrotropical and Oriental regions (Sinclair & Cumming, 2017), which
is characterized by pubescent eyes (short ommatrichia), slender hind femora and mouthparts
similar to Stenoproctus. Syneproctus gen. nov. diers by having bare eyes, enlarged hind femora
and Syneches-like proboscis.
We thank Mr. Jorge Caridad (World Amber Museum, Santo Domingo) and his
family for the loan of the piece MNHNSD FOS 17.01 for study, and for its donation to the
Museo Nacional de Historia Natural “Prof. Eugenio de Jesús Marcano”, Santo Domingo. Thanks
also to Claudia Franz (SMF) for the management of the amber collection and Robin Kunz for
photography and digitization of the drawings (SMF). The comments of Carlos Suriel (Editor)
and two anonymous reviewers also improved the manuscript.
Additional information and declarations
Funding. Financial support was provided by the VolkswagenStiftung project 90946 and the
Spanish Ministry of Economy and Competitiveness (project “CRE”, Spanish AEI/FEDER, UE
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[Recibido: 23 de abril, 2019. Aceptado para publicación: 05 de agosto, 2019]