It is the only known microdontine fly with a simple ejaculatory apodeme and sac. All other Microdontinae have an apical triangularly flared portion to the ejaculatory apodeme which fits into a strongly sclerotized cup-shaped sac.
Adapted from original description (Thompson 1969).
Head: Face simple (slightly produced in paragoides); gena absent, eyes bordering on the oral opening; eyes dichoptic in both sexes; occiput evenly developed. Antennae short, about one-half as long as face; aristae short and thickened.
Thorax about as long as broad; pleura bare except anepisternum pilose and metapleura (katatergum + anatergum) with microscopic pile; scutellum without apical spines and fringe; metasternum undeveloped and bare; metathoracic spiracles without pile fringes. Legs simple, with no basal setal patches on the femora and with cicatrices only on the metafemora. Wings without the spurious vein, with all apical crossveins straight.
Abdomen oval, lateral margins slightly emarginate, and rolled under ventrally, with 1st sternum bare and 1st spiracles without pile fringes. Genitalia simple; ejaculatory apodeme simple, apical portion not triangularly flared; ejaculatory sac not sclerotized; ejaculatory process single, short, not posteriorly fused to ejaculatory hood; ejaculatory hood with anterior ventral portion elongate; sustentacular apodeme present, double, fused anteriorly to base of ejaculatory hood, and connected posteriorly by membrane to dorsal infolded surface of penis sheath; cerci elongate.
Very small microdontine flies. Body length: 4-5 mm (Thompson 1969).
In words of Thompson (1969), Paragodon forms the plesiomorphic (primitive) sister group to the rest of the Microdontinae. It is the only known microdontine fly with a simple ejaculatory apodeme and sac. All other Microdontinaehave an apical triangularly flared portion to the ejaculatory apodeme which fits into a strongly sclerotized cup-shaped sac. The other primitive (plesiomorphic) characters which Paragodon displays are: 1) short antennae; 2) underdeveloped and bare metasterna; 3) lack of basal setal patches on the femora; 4) lack of a spurious vein; 5) lack of an appendix on the third vein (R4+5) ; 6) presence of a double sustentacular apodeme; 7) single, free ejaculatory process. The lack of cheeks on the head and the reduced thoracic pile are specialized (apomorphic) conditions.
From Netropical Mexico to Costa Rica.