Rhamphorhynchus muensteri
Rhamphorhynchus /ˌræmfəˈrɪŋkəs/, "beak snout", is a genus of long-tailed pterosaurs in the Jurassic period. Less specialized than contemporary, short-tailed pterodactyloid pterosaurs such as Pterodactylus, it had a long tail, stiffened with ligaments, which ended in a characteristic diamond-shaped vane. The jaws of Rhamphorhynchus housed needle-like teeth, which were angled forward, with a curved, sharp, beak-like tip lacking teeth, indicating a diet mainly of fish and insects.
Although fragmentary fossil remains possibly belonging to Rhamphorhynchus have been found in England, Tanzania, and Spain, the best preserved specimens come from the Solnhofen limestone of Bavaria, Germany. Many of these fossils preserve not only the bones but impressions of soft tissues such as wing membranes. Scattered teeth believed to belong to Rhamphorhynchus have been found in Portugal as well.
Description[]
The largest known specimen of Rhamphorhynchus muensteri (catalog number BMNH 37002) measures 1.26 meters (4.1 ft) long with a wingspan of 1.81 m (5.9 ft).
Skull[]
Contrary to a 1927 report by pterosaur researcher Ferdinand Broili, Rhamphorhynchus lacked any bony or soft tissue crest, as seen in several species of contemporary small pterodactyloid pterosaurs. Broili claimed to have found a two millimeter tall crest made of thin bone that ran much of the skulls length in one Rhamphorhynchus specimen, evidenced by an impression in the surrounding rock and a few small fragments of the crest itself. However, subsequent examination of this specimen by Wellnhofer in 1975 and Bennett in 2002 using both visible and ultraviolet light found no trace of a crest, and both concluded that Broili was mistaken. The supposed crest, they concluded, was simply an artifact of preservation.
The teeth of Rhamphorhynchus intermesh when the jaw is closed and are suggestive of a piscivorous diet. There are twenty teeth in the upper jaws and fourteen in the lower jaws.
History and classification[]
The classification and taxonomy of Rhamphorhynchus, like many pterosaur species known since the Victorian era, is complex, with a long history of reclassification under a variety of names, often for the same specimens.
The first named specimen of Rhamphorhynchus, was brought to the attention of Samuel Thomas von Soemmerring by the collector Georg Graf zu Munster in 1825. von Soermmerring concluded that it belonged to an ancient bird. When further preparation uncovered teeth, Graf zu Münster sent a cast to Professor Georg August Goldfuss who recognised it as a pterosaur. Like most pterosaurs described in the mid 19th century, Rhamphorhynchus was originally considered to be a species of Pterodactylus. However, at the time, many scientists incorrectly considered Ornithocephalus to be the valid name for Pterodactylus. This specimen of Rhamphorhynchus was therefore originally named Ornithocephalus Münsteri. This was first mentioned in 1830 by Graf zu Münster himself. However, the description making the name valid was given by Goldfuss in an 1831 follow-up to Münster's short paper. Note that the ICZN later ruled that non-standard Latin characters such as ü would not be allowed in scientific names, and the spelling münsteri was emended to muensteri by Richard Lydekker in 1888.
In 1839, Münster described another specimen he considered to belong to Ornithocephalus (i.e. Pterodactylus), with a distinctive long tail. He named it Ornithocephalus longicaudus, meaning "long tail", to differentiate it from the specimens with short tails (the true specimens of Pterodactylus).
In 1845, Hermann von Meyer officially emended the original species Ornithocephalus münsteri to Pterodactylus münsteri, since the name Pterodactylus had been by that point recognized as having priority over Ornithocephalus. In a subsequent 1846 paper describing a new species of long-tailed 'pterodactyl', von Meyer decided that the long-tailed forms of Pterodactylus were different enough from the short-tailed forms to warrant placement in a subgenus, and he named his new species Pterodactylus (Rhamphorhynchus) gemmingi after a specimen owned by collector Captain Carl Eming von Gemming that was later by von Gemming sold for three hundred guilders to the Teylers Museum in Haarlem.[9] It was not until 1847 that von Meyer elevated Rhamphorhynchus to a full-fledged genus, and officially included in it both long-tailed species of Pterodactylus known at the time, R. longicaudus (the original species preserving a long tail) and R. gemmingi. The type species of Rhamphorhynchus is R. longicaudus; its type specimen or holotype also was sold to the Teylers Museum, where it still resides as TM 6924.
The original species, Pterodactylus muensteri, remained misclassified until a re-evaluation was published by Richard Owen in an 1861 book, in which he renamed it as Rhamphorhynchus münsteri.[11] The type specimen of R. muensteri, described by Münster and Goldfuss, was lost during World War II. If available, a new specimen or neotype is designated the type if the original is lost or deemed too poorly preserved. Peter Wellnhofer declined to designate a neotype in his 1975 review of the genus, because a number of high quality casts of the original specimen were still available in museum collections. These can serve as plastotypes.
By the 1990s (and following Wellnfofer's consolidation of many previously named species), about five species of Rhamphorhynchus were recognized from the Solnhofen limestone of Germany, with a few others having been named from Africa, Spain, and the UK based on fragmentary remains. Most of the Solnhofen species were differentiated based on their relative size, and size-related features such as relative length of the skull.
In 1995, pterosaur researcher Chris Bennett published an extensive review of the currently recognized German species. Bennett concluded that all the supposedly distinct German species were actually different year-classes of a single species, R. muensteri, representing distinct age groups, with the smaller species being juveniles and the larger adults. Bennett's paper did not cover the British and African species, though he suggested these should be considered indeterminate members of the family Rhamphorhynchidae and not necessarily species of Rhamphorhynchus itself. Despite the reduction of the genus to a single species, the type species remains R. longicaudus.
Paleobiology[]
Gallery[]
