Biomedical subjects

Jin Meng

Publications and source records attributed to Jin Meng.

5 recordsLinked to original sources

PubMed2006

A Mesozoic gliding mammal from northeastern China.

Gliding flight has independently evolved many times in vertebrates. Direct evidence of gliding is rare in fossil records and is unknown in mammals from the Mesozoic era. Here we report a new Mesozoic mammal from Inner Mongolia, China, that represents a previously unknown group characterized by a highly specialized insectivorous dentition and a sizable patagium (flying membrane) for gliding flight. The patagium is covered with dense hair and supported by an elongated tail and limbs; the latter also bear many features adapted for arboreal life. This discovery extends the earliest record of gliding flight for mammals to at least 70 million years earlier in geological history, and demonstrates that early mammals were diverse in their locomotor strategies and lifestyles; they had experimented with an aerial habit at about the same time as, if not earlier than, when birds endeavoured to exploit the sky.

Animals↗

PubMed2006

A new Early Oligocene peradectine marsupial (Mammalia)from the Burqin region of Xinjiang, China.

Tertiary marsupial records are very scarce in Asia. A new peradectine marsupial, Junggaroperadectes burqinensis gen. et sp. nov., is reported from the Early Oligocene Keziletuogayi Formation in the Burqin region, Xinjiang, China. This new species is based on a single right upper M2. The tooth possesses a straight centrocrista, a characteristic of peradectines. Its main cusps lean buccally, with the paracone being smaller and lower than the metacone. The conules and stylar cusps are weakly developed. These characters distinguish J. burqinensis from Euro-American Tertiary peradectines, but they also imply a close phylogenetic relationship to Siamoperadectes and Sinoperadectes, two Asian Early Miocene peradectines.

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PubMed2006

Tongue swelling in the recovery room: a case report and discussion of postoperative angioedema.

We present a case of potentially life-threatening postoperative swelling of the tongue and oropharynx that developed in the postanesthesia care unit in a patient taking lisinopril. The principal treatment of angioedema is the discontinuation of the precipitating agent and airway management. Patients with swelling limited to the face and oral cavity may only require monitoring. However, those with swelling in the floor of the mouth, tongue, and supraglottic or glottic areas should have their airway secured by tracheal intubation immediately. Early intubation in patients displaying these characteristics may decrease the incidence of emergent surgical airways. Angioedema is self-limiting, and the swelling usually resolves spontaneously in two to 3 days. Proper identification of angiotensin-converting enzyme inhibitor-associated angioedema requiring a timely airway intervention may reduce mortality, and recognition of its self-limiting course can prevent unnecessary tracheostomy.

Angioedema↗

PubMed2005

Stem Lagomorpha and the antiquity of Glires.

We describe several fossils referable to Gomphos elkema from deposits close to the Paleocene-Eocene boundary at Tsagan Khushu, Mongolia. Gomphos shares a suite of cranioskeletal characters with extant rabbits, hares, and pikas but retains a primitive dentition and jaw compared to its modern relatives. Phylogenetic analysis supports the position of Gomphos as a stem lagomorph and excludes Cretaceous taxa from the crown radiation of placental mammals. Our results support the hypothesis that rodents and lagomorphs radiated during the Cenozoic and diverged from other placental mammals close to the Cretaceous-Tertiary boundary.

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PubMed2005

Large Mesozoic mammals fed on young dinosaurs.

Mesozoic mammals are commonly portrayed as shrew- or rat-sized animals that were mainly insectivorous, probably nocturnal and lived in the shadow of dinosaurs. The largest known Mesozoic mammal represented by substantially complete remains is Repenomamus robustus, a triconodont mammal from the Lower Cretaceous of Liaoning, China. An adult individual of R. robustus was the size of a Virginia opossum. Here we report a new species of the genus, represented by a skeleton with most of the skull and postcranium preserved in articulation. The new species is 50% larger than R. robustus in skull length. In addition, stomach contents associated with a skeleton of R. robustus reveal remains of a juvenile Psittacosaurus, a ceratopsian dinosaur. Our discoveries constitute the first direct evidence that some triconodont mammals were carnivorous and fed on small vertebrates, including young dinosaurs, and also show that Mesozoic mammals had a much greater range of body sizes than previously known. We suggest that Mesozoic mammals occupied diverse niches and that some large mammals probably competed with dinosaurs for food and territory.

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