BEIJING, May 12 (Xinhua) -- The following is a summary of published science and technology news of China.

ANTARCTIC TELESCOPE

A small Chinese telescope array mounted in Antarctica has started operation to observe exoplanets or Earth-like planets, according to a news release by the Chinese Academy of Sciences (CAS) on Wednesday.

The facility, consisting of four optical telescopes and a near-infrared one, has been installed at China's Zhongshan Station during the country's 38th Antarctic scientific expedition.

The telescope array is set on an equatorial mount, and the aperture of the four telescopes in the optical band is 150 mm and the near-infrared one 200 mm, according to CAS.

REPTILE FOSSIL

Chinese scientists have discovered a fossil of a new species of marine reptiles known as a pachypleurosaur, dating back 244 million years, with the longest tail ever seen for its kind, indicating it may have been an exceptional swimmer.

The pachypleurosaurs were a group of small to medium-sized, lizard-like marine reptiles from the early to middle Triassic Period, and the new species has been named Honghesaurus after the discovery site Honghe Hani and Yi Autonomous Prefecture.

At 25.4 cm, the tail made up more than half the length of the creature, estimated at 47.1 cm. Scientists found it had a total of 121 vertebrae, including 69 caudal, or tail, vertebrae, beating the previous record of 58 caudal vertebrae in other pachypleurosaurs.

SLEEP DURATION

Researchers have found that approximately seven hours is the optimal sleep duration for the middle-aged and elderly, according to a study recently published in the journal Nature Aging.

A Chinese research team from Fudan University studied about 500,000 participants from the UK Biobank, aged 38 to 73. They identified a nonlinear association between sleep duration and cognition and mental health.

Further analysis showed that both insufficient and excessive sleep durations were strongly associated with a decline in their cognition, while stable sleep duration led to better cognitive ability and mental health.