Yui Takahashi

An Early Triassic Ichthyopterygian Fossil from the Osawa Formation in Minamisanriku Town, Miyagi Prefecture, Japan

Abstract. The ichthyopterygian Utatsusaurus hataii Shikama et al. 1978 is the only valid reptilian taxon known from the Lower Triassic Osawa Formation in Minamisanriku Town, Miyagi Prefecture, which records the recovery of the marine ecosystem shortly after the end-Permian mass extinction. In this paper, we describe a fragmentary specimen of an indeterminate ichthyopterygian which is distinguished from Utatsusaurus hataii based on rib morphology. The discovery of a previously unknown ichthyopterygian implies that the taxonomic diversity of the reptilian fauna of this formation is higher than previously assumed.

Coproporus electron sp. nov., the first tachyporine rove beetle in Dominican amber (Coleoptera, Staphylinidae)

A new fossil rove beetle, Coproporus electron Yamamoto, sp. nov., is described from Dominican amber (early Middle Miocene). This is the first fossil of the genus and also represents the first formal record of the subfamily from Dominican amber. Coproporus electron even stands for the first fossil tachyporine described from the Neotropical region. Our finding is congruent with the hypothesis that the ancient forests that produced Dominican amber were long-vanished tropical forests, as modern members of Coproporus are restricted primarily to wet tropical regions.KurzfassungEin neuer fossiler Kurzflügler, Coproporus electron Yamamoto, sp. nov., wird aus dem Dominikanischen Bernstein (frühes Mittel-Miozän) beschrieben. Dieser erste fossile Vertreter der Gattung stellt gleichzeitig auch die erste offizielle Entdeckung der Unterfamilie Tachyporinae aus Dominikanischem Bernstein dar. Coproporus electron sp. nov. steht desweiteren für die ersten fossilen Tachyporinae überhaupt, die aus der Neotropis beschrieben werden. Unsere Entdeckung deckt sich mit der Hypothese, dass die ehemaligen Wälder, die Dominikanischen Bernstein produzierten, vor langer Zeit verschwundene tropische Wälder waren, da moderne Vertreter von Coproporus vor allem auf feucht-tropische Regionen beschränkt sind.

First discovery of fossil Coloninae in Cretaceous Burmese amber (Coleoptera, Staphylinoidea, Leiodidae)

Coloninae is a tiny and distinctive subfamily of the highly diverse family Leiodidae (round fungus and small carrion beetles). Although only one leiodid fossil is known from the Mesozoic, its taxonomic position and classification are doubtful. We describe the first definitive Coloninae fossil, Colon burmiticum Yamamoto sp. nov., from Upper Cretaceous amber of Myanmar. Our finding sheds light on the origin and early evolutionary history of this peculiar genus and its subfamily.KurzfassungDie Coloninae sind eine kleine und unverwechselbare Unterfamilie der vielfältigen Gruppe der Familie Leiodidae, auch runde Pilzkäfer genannt. Obwohl es nur einen einzigen fossilen Vertreter der Leiodidae aus dem Mesozoikum gibt, ist seine taxonomische Position und Klassifizierung zweifelhaft. Hier beschreiben wir das erste eindeutige Fossil der Coloninae, Colon burmiticum Yamamoto sp. nov., aus dem Oberkreide-Bernstein aus Myanmar (Burma). Unsere Entdeckung beleuchtet den Ursprung und die frühe Evolutionsgeschichte dieser eigenartigen Gattung und sogar der Unterfamilie.

The Compression Mating Fossil of Sciarid Fly (Diptera: Sciaridae) from Shiobara, Tochigi Prefecture, Japan

Abstract. Preservations illustrating insect reproductive behaviors are much rarer in compression fossils than in amber. We discovered a copulating compression fossil of the sciarid flies from the Pleistocene Shiobara Group, Tochigi Prefecture, Japan, which is briefly described herein. The specimen represents one of the rare examples of a compression fossil showing mating dipteran insects. This finding implies that the small bodies of sciarid flies which readily fall onto the water surface may have contributed to the preservation of our copulating fossil. Moreover, the depositional environment of the paleo-Shiobara Lake was the main factor that served to preserve this specimen.