Family Ammotrechidae Roewer 1934

Ammotrechidae Roewer, 1934: 578-579 ; Kästner, 1933-1935: 296; Birula, 1938: 12; Mello-Leitão, 1938b: 10-11; Muma, 1951: 122 ; Kaestner, 1968: 225; Muma, 1970a: 44; Muma, 1971b: 3-4 ; Muma, 1976: 9; Muma, 1982: 103-104; Maury, 1985b: 76-77, 79; Muma, 1989: 45-46; El-Hennawy, 1990: 23; Armas, 1993: 41; Armas, 2004: 32 .

Diagnosis:  Roewer (1934) characterized the family as follows:

"Solifugae, am Prosoma mit teilweise vom Propeltidium getrenntem Lobus exterior, mit Plagula mediana, die von den Arci anteriores nur unscharf getrennt ist. Die Arci posteriores kurz und nach hinten divergierend (Abb. 22). Propeltidium, Arci, prosomale und vordere opisthosomale Tergite oft, besonders beim ♂, mit Dornen oder Dornborsten besetzt, die dann beim ♂ auch auf der Dorsalfläche der Oheliceren aufzutreten pflegen (Abb. 329, c, d und 336, a). Die paarigen Stigmen des Opisthosoma sind frei sichtbar und nicht durch besondere Haarpolster oder Zähnchenkämme am Hinterrand ihrer Sternite geschützt (wie Abb. 190).  Die opisthosomalen Sternite tragen weder beim ♂ noch beim ♀ echte Ctenidien, und das Genitalsternit der ♀♀ ist artlich nicht differenziert, sondern normal gebaut.
         Das GebiB der Cheliceren ist bei beiden Geschlechtern gleich gestaltet und ohne Differenzierung der Zähne in Form und Zahl.  Der unbewegliche Finger trägt 2 oder 3 (im ersteren Falle fast gleich große, im anderen Falle ungleich große, deren erster dann kleiner als der dritte und größer als der zweite ist) Vorderzähne (selten sogar 4), 1 (selten 2) kleinen Zwischenzahn, 1 (von allen größten) Hauptzahn und 3-4 (selten 2 oder mehr als 4) kleinere laterale und mediale Wangenzähne.  Der bewegliche Finger hat stets nur 1 Vorderzahn, 1 (selten 2) Zwischenzahn und 1 (stets größten) Hauptzahn, neben dem bei vielen Formen noch 1 medialer, etwas proximal stehender Wangenzahn auftritt. Das Flagellum des ♂ bildet eine durchsichtige Spelze, deren dorsaler und ventraler Rand stets medialwärts mehr oder minder eingerollt und fein befranst ist. Diese Spelze ist stets unbeweglich, also nicht drehbar, mit ihrer verjüngten Spitze nach vorn gerichtet und mit einem längsovalen (nicht kreisrunden) Ring verstärkten Chitins an der Medialfläche des unbeweglichen Fingers etwa in der Höhe des Haupt- oder des 1. medialen Wangenzahnes befestigt (Abb. 329, d usw.). Besonders differenzierte Borsten eines "Flagellum-Komplexes" treten nicht auf.
         Pedipalpen mit unbeweglichem Tarsus, nur behaart oder an Tibia und Metatarsus oft mit ventralen Paaren langer Dornborsten oder kurzer Dornen, meist auch mit Zylinderborsten, diese oft auch beim ♀ vorhanden; eine papillöse Scopula fehlt immer.
         Laufbeine normal gebaut und nicht zum Graben eingerichtet; 1. Tarsus stets 1-g1iedrig, stets ohne eine Spur von Endkrallen und wie die übrigen Glieder des 1. Beines unbewehrt und ohne Dornen. 2. und 3. Bein gleichartig bewehrt: Tibia dorsal mit oder ohne (artlich konstantem) Enddorn, ventral mit 2 apikalen Dornborsten, Metatarsus dorsal mit einer Längsreihe aus 3 oder 5 Dornen, ventral meist mit 1.1.2 Dornen. Der 2. und 3. Tarsus ist meist 1-, seltener 2-gliedrig; im ersteren Falle mit gattungsweise konstanter ventraler Bedornung, im zweiten Falle ventral unbewehrt. Ein dorsaler Enddorn fehlt dem 2. und 3. Tarsus stets, ihre Endkrallen sind kahl mit einem Unguiculus, der viel kürzer ist als ihr Pedunculus. - Am 4. Bein sind alle Glieder, einschließlich des Tarsus, dorsal unbewehrt und weder mit Dornborsten noch mit Dornen bewehrt; Tibia und Metatarsus tragen ventral einzeln oder zu Paaren stehende Dornen oder Dornborsten. Der Tarsus ist 1-4-gliedrig (siehe die Subfamilien) und ventral gattungsweise konstant bedornt, selten - am 4-g1iedrigen Tarsus - ganz unbewehrt, seine Endkrallen sind ebenso gebaut wie die des 2. und 3. Tarsus. Der Pulvillus des 2. -4. Tarsus ist nicht sonderlich gespalten."

[Solifugae, which on the prosoma have the exterior lobes of propeltidium partially separated, with  the plagula mediana only partially separated from arci anteriores.  Posterior arci short and diverging posteriorly (Fig. 22).  Propeltidium, arci, prosoma and anterior opisthosomal tergite often, especially in males, bearing spines or spinelike setae, which in the male, also occur on the dorsal surface of the chelicerae (Fig. 329 c, d, and 326a).  The paired stigma of the opisthosoma are freely visible and not protected by special setae or denticles at the posterior end of their sternites (Fig. 190).  The opisthosomal sternites of both ♂ and ♀ lack genuine ctenidia, and the genital sternite is not specifically differentiated, but is normally developed.
         The dentition of the chelicerae is similar in both sexes, without differentiation of the teeth in form and number. The fixed finger bears 2 or 3 anterior teeth (rarely even 4), which in the first case are similar in size, and in the other case are unequal in size, with the first being smaller than third and larger than the second), 1 (rarely 2) small intermediate teeth, 1 (largest of all) main tooth and 3-4 (rarely 2 or more than 4) smaller lateral and medial cheek teeth.  The movable finger always has only 1 anterior tooth, 1 (rarely 2) intermediate teeth and 1 (always the largest) main tooth, besides which in many species arises 1 medial, somewhat proximally situated cheek tooth.  The flagellum of the ♂ forms a transparent husk, whose dorsal and ventral edge are always more or less rolled up medially and finely fringed.  This husk is always immovable, thus not rotatable, and is attached, with its tapered point directed forward, by a longitudinal, oval (not circular), reinforced chitinous ring to the medial surface of the fixed finger approximately at the level of the main tooth or of the 1st medial cheek tooth (fig. 329, d etc.).  Particularly differentiated bristles of a "flagellum complex" do not arise.
         Pedipalps with immovable tarsus, only setose, or on tibia and metatarsus often with ventral pairs of long spine-like bristles or short spines, usually also with cylinder bristles, this arrangement often also present on ♀; a papillose scopula is always missing.
         Running legs normally built and not modified for digging; 1st Tarsus always 1-segmented, always without a trace of terminal claws and, and like the remaining segments of the 1st leg unarmed and lacking spines.  2nd and 3rd legs each armed the same: tibia with or without dorsal terminal spine (constant within a species), with 2 ventral  apical spinelike bristles, metatarsus with a dorsal longitudinal row of 3 to 5 spines, usually with 1.1.2 ventral spines.  The 2nd and 3rd tarsi are usually 1 -, rarely 2-segmented (in the first case the ventral spination is constant within a genus, in the second case the tarsi are ventrally unarmed).  A dorsal terminal spine is always missing from the 2nd and 3rd tarsi, the terminal claws of which are bald, and the unguiculus is much shorter than the pedunculus.  The 4th leg is dorsally unarmed on all segments, including the tarsus, and bears neither spinelike bristles nor spines; the tibia and metatarsus carry individual or paired erect ventral spines or spinelike bristles. The tarsus is 1- to 4-segmented (see the subfamilies) and adorned consistenty within each genus, rarely - on the 4-segmented tarsus - completely unarmed, with the terminal claws just as those of the 2nd and 3^rd tarsi. The pulvilli of the 2nd – 4th tarsi are not particularly divided."

Fig. 22 =  Dorsal view of prosoma of Ammotrecha sp.; Fig. 329c = Saronomus capensis Kraepelin ♂, chelicerae, propeltidium and anterior free tergites showing distribution of spines, in dorsal view; Fig 329d = Saronomus capensis Kraepelin ♂, right chelicera with medial flagellum; Fig 336a = Neocleobis solitarius (Banks), ♂, right chelicera, right half of propeltidium hälfte with pedipalp; Fig. 190 = Paired stigma on the third opisthosomal sternite of Solpuga venator Pocock, seen.from the outside seen (after preparation) [st = sternite surface with long, strong setae; r = chitin ring around spiracular opening; s = spiracular opening; t = intersegmental membrane at the posterior margin of  the sternite].
 

Mesal view of chelicera of male Ammotrechula catalinae Muma from Sonora, Mexico, showing flagellum (photo by Warren E, Savary).

Muma (1951) characterized the family as follows:

         "Solpugida with exterior lobes of propeltidium partially separated from the peltidium.  Propeltidium with anterior margin recurved. Median plagula of peltidium indistinctly separated from anterior arci.  Posterior arci of parapeltidium short and diverging posteriorly.  Propeltidium, peltidium, parapeltidium, mesopeltidium, metapeltidium, anterior abdominal tergite, and dorsal surfaces of the chelicerae often covered with spines.  Paired spiracles of the abdomen distinct and not protected.  The first postspiracular abdominal sternite of the males does not bear true ctenidia.  Genital sternite of females not distinctly, specifically differential.
         Cheliceral dentition similar in males and females but often exhibiting sexual dimorphism in a modification of the fixed finger and teeth of the male.  The fixed finger bears three primary teeth that may or may not be separated by a variable number of intermediate teeth. The movable finger bears two primary teeth, a variable number of intermediate teeth, and often a mesal tooth just mesad of the basal primary tooth.  A mesal and ectal row of fondal teeth occurs between the fingers of the chelicerae.  The male flagellum consists of an immovable, transparent, elliptical membrane of which the dorsal and ventral margins are frequently finely fringed and bent or curled mesally.  The anterior end of the flagellum is usually attenuated, and the flagellum is attached to the fixed finger by an elliptical chitinized ring at or about the vertical level of the fondal teeth.
         Palpus with an immovable tarsus; metatarsus and tibia often bear a series of short or long paired spines in addition to the usual hairs and cylinder bristles.  There is no scopula on the palpus.
         Walking legs normal.  Tarsi of first legs unsegmented and without claws or spines.  Tarsi of second and third legs usually unsegmented, rarely with two segments and bearing a generically variable series of ventral spines.  There is no dorsal terminal spine on the tarsi of the second or third legs.  Tarsi of fourth legs with one to four segments and bearing a generically variable series of ventral spines.  Leg spination otherwise variable."

...and later (1976) offered the following characterization:

"Tiny to moderate-sized (5 -22 mm). short-legged to long-legged solpugids with a terminal anus. The exterior lobes of the propeltidiurn are free to completely fused. The tarsi of legs 1 lack claws.  The tarsal segmentation of legs 1 to 4 is variable: 1, 1-2, 1-2, 1-4; and the tarsal claws are smooth.  The male cheliceral flagellum is a paraxially immovable, essentially oval, membranous structure attached to the mesial surf'ace by a disk. The female genital opcrcula arc not differentiated f'ronm other abdodimal sternites and are not specifically variable, except perhaps in the ratio of length to width and in the length of the caudal notch."

Distribution:  North, Central and South America.
 
Included taxa: At present, 87 living species and a single fossil species are assigned to this family.  They are distributed among 21 genera, which in turn are distributed among five subfamilies.  Ammotrecha (10 species), Ammotrechella (17 species), Ammotrechesta (5 species), Ammotrechinus (1 species), Ammotrechula (12 species), Antillotrecha (2 species), Campostrecha (1 species), Dasycleobis (1  species), Neocleobis (1 species), and Pseudocleobis (20 species), are placed together in the subfamily Ammotrechinae, whose members are broadly distributed through North, Central, and South America.  The monotypic genus Mortola of Argentina is placed by itself in the subfamily Mortolinae.  Nothopuga (2 species, both from Argentina) is the sole genus in the Nothopuginae.  The four Argentinian species comprising the genus Oltacola are assigned to the subfamily  Oltacolinae.  Branchia (3 species), Chinchippus (1 species), Innesa (1 species), Procleobis (1 species), and Saronomus (1 species) are placed in the Saronominae.  Three living species [Chileotrecha atacamensis,  Eutrecha longirostris, and Xenotrecha huebneri], and the sole known fossil species [Happlodontus proterus], are not presently assigned to any of the recognized subfamilies.  
        Roewer's original characterization of the family has been accepted by subsequent authors, as has his recognition of genera  based primarily on tarsal segmentation and the number and arrangement of ventral spine-like setae on the tarsi.  However, Muma (1970) observed that separation on this basis is problematic, as the ventral spinelike setae are either very difficult to distinguish or variation in their number and arrangement exists.  Nonetheless, he chose to retain Roewer's (1934) generic concepts "even though inconsistencies, heterogeneities, and synonymies are indicated."  Muma (1976) later reiterated that " C. F. R Roewer's generic classification, based on tarsal segmentation, tarsal spinelike setal patterns, tibial spinelike setal patterns, and basic cheliceral dentition, is generically and specifically variable, difficult to use, and probably invalid.  A generic revision is needed."   Maury (1976) acknowledged past criticisms of Roewer's classification, but noted that it still appeared useful for the Ammotrechidae, at least for differentiating the subfamilies, and that other characters tended to corroborate the classification.  He noted, in particular, the the lack of spines on the tarsi of Oltacolinae (present in all other subfamilies), and the articulated, movable tarsi of the Nothopuginae (in all other subfamilies, the tarsus and protarsus combine to form a unique, immovable piece).
     The five subfamilies can be identified using the following tabular key, modified from Maury (1976):
 

	A	B	C	D	E
Saronominae	1	1	yes	no	yes
Ammotrechinae	1	3	yes	no	yes
Oltacolinae	2	4	no	no	yes
Mortolinae	2	3	yes	no	yes
Nothopuginae	2	2	yes	yes	no

A:  Number of segments in tarsi of legs II and III; 
B:  Number of segments in the tarsus of leg IV; 
C:  Spines present on the tarsi of legs II-IV; 
D: Tarsi of pedipalps articulated and movable; 
E:  Intermediate tooth present on movable finger of chelicerae.