Corresponding author: Francisco Hita Garcia (
Academic editor: M. Borowiec
In this study we provide an update to the taxonomy of the ant genus
Hita Garcia F, Fisher BL (2015) Taxonomy of the hyper-diverse ant genus
The genus
On a global scale,
In this study we report the first record of the presence of the Afrotropical
The collection abbreviations follow
The material examined for this study and the previous Malagasy
Schematic line drawings of
Pubescence and pilosity are often of high diagnostic value within the genus
The
Most of the abovementioned, mostly non-native, groups possess twelve-segmented antennae and a triangular to dentiform sting appendage (except the
One intriguing finding of the recent revisions (
The most closely related ants seem to belong to the comparatively species-rich
The Malagasy
In summary, we were able to identify a highly unique Malagasy
Overview of all 19 Malagasy species groups recognised in this study. For each group we provide number of Malagasy species, zoogeographical affinities, number of antennal segments, shape of sting appendage and anterior clypeal margin, the last taxonomic revision, and habitat preferences. The following abbreviations are used for zoogeographical affinities: AFR=Afrotropical, INA=Indo-Australian, MAD=only Madagascar, MAL=Malagasy (Madagascar plus islands of the Southwest Indian Ocean), NEA=Nearctic, ORI=Oriental, T=panglobal tramp.
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6 |
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MAD | 11 | spatulate | notched |
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dry forests, savanna, grassland, anthropogenic habitats |
8 |
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MAD | 11 | spatulate | notched |
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dry forests, savanna, grassland, anthropogenic habitats |
10 |
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MAD | 11 | spatulate | notched |
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predominantly lowland or montane rainforests |
2 |
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MAL | 11 | spatulate | notched |
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dry and humid forests |
6 |
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MAD | 11 | spatulate | notched |
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lowland or montane rainforests |
5 |
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MAD | 11 | spatulate | notched | Hita Garcia and Fisher 2014 | lowland or montane rainforests |
5 |
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MAD | 11 | spatulate | notched | Hita Garcia and Fisher 2014 | dry forests, savanna, grassland |
21 |
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MAD | 11 | spatulate | notched | in preparation | predominantly lowland or montane rainforests |
20 |
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MAL | 11 | spatulate | notched | Hita Garcia and Fisher 2014 | mostly lowland or montane rainforests, rarely dry forests or open habitats |
1 |
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MAD | 11 | spatulate | notched | Hita Garcia and Fisher 2014 | lowland or montane rainforests |
2 |
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MAD | 11 | spatulate | notched |
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dry forest |
22 |
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NEA, AFR, MAD, ORI & INA | 11 | spatulate | notched |
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predominantly lowland or montane rainforests |
1 |
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AFR & MAL | 11 | spatulate | notched |
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dry forests, savanna, grassland, anthropogenic habitats |
3 |
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AFR, ORI, INA & MALT | 12 | triangular to dentiform | notched |
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habitat generalist |
1 |
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ORI, INA & MAL, T | 12 | triangular to dentiform | notched |
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habitat generalist |
2 |
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AFR & MAL | 12 | triangular to dentiform | entire |
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anthropogenic habitats, spiny forest, thicket, coastal and littoral forests, woodland |
1 |
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AFR & MAD | 12 | triangular to dentiform | entire | in this study | dry forest |
7 |
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AFR, MAL & MAL, T | 12 | triangular to dentiform | entire | in preparation | habitat generalist |
2 |
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MAD | 12 | triangular to dentiform | entire |
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lowland or montane rainforests |
125 |
The species group key presented here is based on the one published in
1 | Species with distinctly branched hairs, usually a mixture of simple, bifid, and trifid hairs (Fig. |
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– | Species without branched hairs; hairs present neither bifid nor trifid, either with simple pilosity (Fig. |
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2 | Antennae 12-segmented (Fig. |
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– | Antennae 11-segmented (Fig. |
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3 | Anterior clypeal margin with distinct median impression (Fig. |
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– | Anterior clypeal margin always entire and convex, never with distinct median impression (Fig. |
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4 | Propodeum armed with long to extremely long spines (PSLI 30–49), at least 2 to 3 times longer than metapleural lobes (Fig. |
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– | Propodeum either unarmed (Fig. |
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5 | Lateral portion of clypeus prominent, raised to a tooth or denticle in full-face view (Fig. |
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– | Lateral portion of clypeus never modified as above (Fig. |
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6 | Head in full-face view relatively thin (CI < 80) and antennal scapes very long (SI > 120) (Fig. |
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– | Head in full-face view relatively thicker (CI > 85) and antennal scapes conspicuously much shorter (SI < 92) (Fig. |
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7 | Petiolar node and postpetiole strongly squamiform, petiolar node with anterior and posterior faces parallel and well developed, straight dorsum; petiole and postpetiole always completely unsculptured, smooth, and shining; standing pilosity scarce or absent on dorsal mesosoma and waist segments, first gastral tergite without standing pilosity (Fig. |
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– | Character combination never as above; petiole and postpetiole variably shaped, especially postpetiole never squamiform as above (Fig. |
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8 | Pronotum anterodorsally with distinct protuberance or bulge (Fig. |
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– | Pronotum anterodorsally without any protuberance or bulge (Fig. |
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9 | First gastral tergite with strongly appressed pubescence of varying length and without any standing hairs (Fig. |
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– | First gastral tergite usually with long, erect to suberect pilosity (Fig. |
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10 | Antennal scrobes well developed with sharply defined posterior and ventral margins (Fig. |
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– | Antennal scrobes usually weakly developed, never with well-defined posterior and ventral margins (Fig. |
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11 | In profile petiolar node rectangular nodiform with sharply angled anterodorsal and posterodorsal margins; both waist segments strongly sculptured (Fig. |
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– | Petiolar node rectangular nodiform with conspicuously rounded anterodorsal and/or posterodorsal margins (Fig. |
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12 | Propodeum armed with short to moderately long spines (PSLI 18–25); dorsum of head and mesosoma without any standing pilosity (Fig. |
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– | Propodeum armed with very long spines (PSLI 50–53); dorsum of head and mesosoma with standing pilosity (Fig. |
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13 | Larger species (HW 0.82–1.03; WL 1.14–1.48); mesosoma comparatively long and slender (LMI 35–37) without distinct margination between lateral and dorsal mesosoma; propodeal spines always very long (PSLI 38–43); body colouration always dark brown to black (Fig. |
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– | Character combination never as above, especially mesosoma either with strong margination between sides and dorsum (Fig. |
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14 | Dorsum of mesosoma generally completely unsculptured (Fig. |
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– | Mesosoma usually strongly sculptured (Fig. |
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15 | Propodeal spines long and metapleural lobes short (Fig. |
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– | Propodeal spines/teeth comparatively short and metapleural lobes of almost similar size (Fig. |
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16 | Mandibles always unsculptured, smooth, shining (Fig. |
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– | Mandibles variably sculptured (Fig. |
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17 | Antennal scrobes very well developed and distinctly impressed with sharply defined posterior and ventral margins; scrobes with very conspicuous median longitudinal scrobal carina, carina always ending between posterior eye margin and posterior margin of scrobe (Fig. |
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– | Character combination never as above; usually antennal scrobes either almost absent (Fig. |
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18 | Sculpture on head, mesosoma, and waist segments strongly reduced: head usually very weakly sculptured (especially posteriorly) (Fig. |
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– | Sculpture never as strongly reduced as above, head always and to a great extent sculptured (Fig. |
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19 | Mesosoma only weakly marginate between lateral and dorsal mesosoma, instead sides of mesosoma generally rounding more or less smoothly onto the dorsum (Fig. |
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– | Mesosoma usually with strong margination between lateral and dorsal mesosoma (Fig. |
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20 | Relatively large species (HW 0.85–0.97; WL 1.21–1.48); SI relatively high (SI 89–104); propodeal spines very long to extremely long (PSLI 35–68); petiolar node in profile clublike, elongate and longer than high, posterodorsal angle situated higher than anterodorsal (Fig. |
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– | Character combination never as above, most species much smaller with lower SI and shorter propodeal spines, a differently shaped petiolar node, and with less abundant and shorter pilosity (Fig. |
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21 | Mesosomal outline in profile relatively flat, comparatively low and elongated (LMI 35–39) (Fig. |
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– | Character combination never as above; mesosoma usually more compact and higher (LMI usually conspicuously above 40, very rarely below) (Fig. |
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22 | Mesosoma strongly marginate from sides to dorsum (Fig. |
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– | Character combination never as above, especially dorsum of mesosoma usually with conspicuous sculpture along its entire length (Fig. |
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23 | Petiolar node in profile dorsally conspicuously anteroposteriorly compressed and strongly narrowing towards apex, giving node a triangular or sharply cuneiform appearance; both waist segments always completely unsculptured, smooth and shiny (Fig. |
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– | Petiolar node variably shaped: rectangular nodiform (Fig. |
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24 | Dorsum of mesosoma longitudinally rugose/rugulose (Fig. |
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– | Dorsum of mesosoma conspicuously reticulate-rugose, especially anteriorly (Fig. |
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25 | Dorsum of mesosoma conspicuously reticulate-rugose throughout its length (Fig. |
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– | Dorsum of mesosoma longitudinally rugose/rugulose (Fig. |
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26 | Eyes relatively large (OI 25–26); petiolar node in profile distinctly squamiform and anteroposteriorly compressed (Fig. |
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– | Eyes smaller than above, usually significantly so; petiolar node weakly cuneiform to rectangular nodiform and variably sculptured (Fig. |
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27 | Petiolar node usually rectangular nodiform with more or less sharply angled anterodorsal and posterodorsal margins (Fig. |
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– | Petiolar node usually squamiform (Fig. |
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28 | Pilosity and pubescence on first gastral tergite usually consisting of abundant, long, erect to suberect hairs on top of scarce, much shorter, appressed to decumbent pubescence (Fig. |
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– | Pilosity and pubescence on first gastral tergite variable: either with few moderately long, appressed to decumbent pubescence in combination with several much longer, fine, and erect hairs (Fig. |
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Body in profile.
Antennal funiculus and sting appendage (within black ellipses).
Anterior head in dorsal view (anterior clypeal margin within black ellipses).
Mesosoma in profile (black arrows indicate propodeal spines/teeth area).
Head in full-face view and body in profile.
Mesosoma and waist segments in profile (waist segments within black ellipses).
Body in profile (anterodorsal pronotum within black circles).
First gastral tergite in profile.
Lateral head in profile (antennal scrobe area within black ellipses).
Petiole and postpetiole in profile.
Posterior head and mesosoma in profile (black arrows indicate propodeal spines/teeth.
Body in profile.
Mesosoma in dorsal view.
Mesosoma in profile (black arrows indicating propodeal spines/teeth) and petiole in dorsal view (within black ellipse).
Anterior head in dorsal view and waist segments in profile.
Head (without mandibles) in profile (antennal scrobe area within black ellipses); mesosoma in dorsal view; body and waist segments in profile.
Head (without mandibles) in dorsal and lateral view; Mesosoma in dorsal view.
Mesosoma, waist segments, and first gastral tergite in profile.
Mesosoma and waist segments in profile; mesosoma in dorsal view.
Mesosoma and waist segments in profile.
Mesosoma in dorsal view.
Petiole and postpetiole in profile.
Mesosoma in dorsal view.
Mesosoma in dorsal view.
Body in profile (black arrows indicate eyes; wait segments within black ellipses).
Petiole and postpetiole in profile.
First gastral tergite in profile.
Twelve-segmented antennae; antennal scapes very long (SI 120–123); anterior clypeal margin entire and clearly convex; frontal carinae well-developed, ending at or approaching posterior head margin; eyes moderate (OI 23–26); anterior face of mesosoma weakly developed, no distinct margination between lateral and dorsal mesosoma; propodeum armed with short triangular to elongate-triangular teeth (PSLI 7–11), propodeal lobes moderately developed, triangular to elongate-triangular, slightly longer and broader than propodeal teeth; petiolar node relatively small, nodiform, with weakly angled anterodorsal and posterodorsal margins, and comparatively long peduncle, petiolar dorsum flat to very weakly convex, node in profile between 1.2 to 1.4 times higher than long (LPeI 73–79), node in dorsal view between 1.2 to 1.3 times longer than wide (DPeI 121–127); postpetiole in profile approximately globular, around 1.0 to 1.1 times higher than long (LPpI 90–98); mandibles striate; clypeus longitudinally rugose/rugulose with well-developed median ruga and usually one or two weaker, sometimes irregular, lateral rugae/rugulae on each side; sculpture on cephalic dorsum irregularly longitudinally rugose to reticulate-rugose; mesosoma laterally irregularly rugulose, dorsally reticulate-rugulose to irregularly rugulose; petiole and postpetiole conspicuously rugulose; ground sculpture on mesosoma and waist segments distinctly reticulate-punctate, much weaker on head; gaster unsculptured, smooth, and shiny; all dorsal surfaces of body with short to moderately long, thick, and apically blunt pilosity; sting appendage triangular to dentiform.
Prior to this study, the
The
Body in profile.
MADAGASCAR: Antsiranana, Réserve Spéciale d’Ankarana, Andrafiabe,
Head much longer than wide (CI 77–79); posterior head margin weakly to moderately concave. Anterior clypeal margin entire and convex. Frontal carinae strongly developed, moderately raised, usually becoming weaker after posterior eye level, approaching or ending at posterior head margin; antennal scrobes very weak to absent. Antennal scapes very long, weakly surpassing posterior head margin (SI 120–123). Eyes moderately large (OI 23–26). Mesosomal outline in profile relatively flat, elongate and low (LMI 35–36), weakly marginate from lateral to dorsal mesosoma; promesonotal suture and metanotal groove absent. Propodeum armed with short, triangular teeth (PSLI 7–11), propodeal lobes moderately developed, triangular to elongate-triangular, slightly longer and broader than propodeal teeth. Petiolar node nodiform with moderately rounded antero- and posterodorsal margins, in profile between 1.2 and 1.4 times higher than long (LPeI 73–79), anterior and posterior faces not parallel, node weakly narrowing towards dorsum, anterodorsal and posterodorsal margins situated at about same height and both weakly to moderately angled, petiolar dorsum flat to very weakly convex; node in dorsal view around 1.2 to 1.3 times wider than long (DPeI 121–127), in dorsal view pronotum around 2.0 to 2.1 times wider than petiolar node (PeNI 47–49). Postpetiole in profile approximately globular, around 1.0 to 1.1 times higher than long (LPpI 90–98); in dorsal view around 1.1 and 1.2 times wider than long (DPpI 113–123), pronotum around 1.7 to 1.8 times wider than postpetiole (PpNI 56–60). Postpetiole in profile appearing distinctly more voluminous than petiolar node, postpetiole in dorsal view around 1.2 to 1.3 times wider than petiolar node (PPI 120–127). Mandibles striate; clypeus longitudinally rugose/rugulose with well-developed median ruga and usually one or two weaker, sometimes irregular, lateral rugae/rugulae on each side; cephalic dorsum between frontal carinae anteriorly towards posterior clypeal margin with three or four distinct but irregularly shaped longitudinal rugae with numerous cross-meshes, halfway between eye level and posterior head margin fluent transition to well-developed rugoreticulum ranging to posterior head margin; scrobal area only weakly sculptured, remainder of lateral head clearly reticulate-rugose. Mesosoma laterally and dorsally conspicuously reticulate-rugose; forecoxae unsculptured, smooth, and shining. Petiole and postpetiole irregularly rugulose, better developed on dorsum than sides. First gastral tergite unsculptured, smooth, and shiny. Ground sculpture on cephalic dorsum between frontal carinae weak, distinctly reticulate-punctate on lateral head, mesosoma, and waist segments, absent from gaster. All dorsal surfaces of body with short to moderately long, thick, and apically blunt pilosity; appressed pubescence on first gastral tergite strongly reduced to absent. Anterior edges of antennal scapes and dorsal (outer) surfaces of hind tibiae with decumbent to suberect hairs. Head and mesosoma reddish brown; waist segments lighter in colour, usually orange brown; mandibles, antennae, and legs yellowish brown.
The name of the new species is a Latin noun and means “cave dweller” or “cave inhabitant”. It refers to the microhabitat where the type series was collected. The species epithet is a nominative noun in apposition.
Currently,
Since
First, we want to thank Tracy Audisio from Darmstadt, Germany, for the line drawings used in this publication. Also, we appreciate the great help of Michele Esposito from CAS with image processing and databasing. We are also thankful to all the current and previous AntWeb imagers: April Nobile, Erin Prado, Estella Ortega, Shannon Hartman, William Ericson, Ryan Perry, Cerise Chen, and Zach Lieberman. Furthermore, we want to express our gratitude to the following curators and/or curatorial staff, who either loaned important material or welcomed FHG to their collections: Mrs Suzanne Ryder, Dr Gavin Broad, and Mrs Natalie Dale-Skey Papilloud from BMNH; Dr Stefan Cover and Dr Gary D. Alpert from MCZ; Dr Giulio Cuccodoro from MHNG; Mrs Isabelle Zürcher-Pfander from NHMB; Dr Brian Brown and Mrs Giar-Ann Kung from LACM; and Dr Eliane De Coninck from RMCA. This study was supported by the National Geographic Society under grant No. 8429-08 and by the National Science Foundation under Grant No. DEB-0072713, DEB-0344731, and DEB-0842395, all granted to BLF. Two Ernst Mayr Travel Grants from the MCZ were granted to FHG to visit the collections in BMNH and MCZ.