The distribution of integumentary structures in a feathered dinosaur

Non-avian theropod dinosaurs with preserved integumentary coverings are becoming more common; but apart from the multiple specimens of Caudipteryx, which have true feathers, animals that are reasonably complete and entirely articulated that show these structures in relation to the body have not been reported. Here we report on an enigmatic small theropod dinosaur that is covered with filamentous feather-like structures over its entire body.

A Chinese triconodont mammal and mosaic evolution of the mammalian skeleton

Here we describe a new triconodont mammal from the Late Jurassic/Early Cretaceous period of Liaoning, China. This new mammal is represented by the best-preserved skeleton known so far for triconodonts which form one of the earliest Mesozoic mammalian groups with high diversity. The postcranial skeleton of this new triconodont shows a mosaic of characters, including a primitive pelvic girdle and hindlimb but a very derived pectoral girdle that is closely comparable to those of derived therians. Given the basal position of this taxon in mammalian phylogeny, its derived pectoral girdle indicates that homoplasies (similarities resulting from independent evolution among unrelated lineages) are as common in the postcranial skeleton as they are in the skull and dentition in the evolution of Mesozoic mammals. Limb structures of the new triconodont indicate that it was probably a ground-dwelling animal.

Skin blood flow changes during routine nursery procedures

OBJECTIVE

The objective of this study was to establish that changes in skin blood flow could serve as an index of pain and discomfort in newborn infants.

METHODS

Skin blood flow changes during intensive care procedures and during morphine administration were measured in a group of newborn infants using a laser Doppler technique. Heart rate, respiratory rate and oxygen saturation were also measured. Changes in skin blood flow and physiologic variables that occurred during procedures were analyzed and compared among procedures.

RESULTS

Measurements were made during 145 procedures in 15 infants 2-32 days old with birth weights of 500-2900 g and gestational ages of 23-37 weeks. Ten of the infants were receiving mechanical ventilation. Skin blood flow increased 27-134% during lancet puncture of the heel, physical handling, standard suctioning and chest physiotherapy, and there were no changes during closed system suctioning. Skin blood flow decreased 35% by 20 min after intravenous morphine. Changes seen in heart rate, respiratory rate and oxygen saturation were generally minimal.

CONCLUSIONS

We conclude that laser Doppler skin blood flow changes could be an index of neonatal pain and discomfort; even noninvasive handling procedures are associated with increases in skin blood flow; and changes in skin blood flow may be more useful than conventional physiologic variables in assessing the response to intensive care nursery procedure.