lack of fossil evidence to settle the debate.

　　"This find suggests that big cats have a deeper evolutionary origin than previously suspected，" said Jack Zeng, a paleontologist of the University of Southern California who led the probe (调查)．

　　Zeng and his team made the find in 2010 in a remote border region in Tibet. The fossil was found stuck among more than 100 bones that were probably deposited by a river that exited a cliff. After three years of careful comparisons with other fossils, using DNA data to build a family tree, the team is convinced the creature was a pantherine felid.

　　The weight of evidence suggests that central or northern Asia is where big cats originated some 16 million years ago. They may have lived in a vast mountain shelter, formed by the uplifting Himalayas, feeding on equally remarkable species such as the Tibetan blue sheep. They then dispersed (分散) into Southeast Asia, evolving (进化) into the clouded leopard, tiger and snow leopard families, and later movements across continents saw them evolve into jaguars and lions.

　　The newly discovered felid has been called Panthera Blytheae, after Blythe Haaga, daughter of a couple who support a museum in Los Angeles, the university said in a news release.

　　语篇解读：本文是一篇科普说明文。一块颅骨的出土推翻了一贯的结论，大型猫科动物起源于中亚，而不是非洲。该出土的颅骨证明了大型猫科动物的生活习性和进化过程。

　　28．According to the passage, why is the evolution of big cats a hot issue?

　　A．Because not many fossils have been found.

　　B．Because they moved across continents.

　　C．Because no equipment was available for accurate analysis.

　　D．Because they have evolved into many different species of felid.

　　解析：选A　细节理解题。根据第三段中的"has been heatedly discussed, and the issue is complicated by a lack of fossil evidence to settle the debate"可知，A项正确。

　　29．Where was the new felid fossil found?

　　A．In Tanzania.　　　　　 B．In Tibet.

　　C．In California. D．In Southeast Asia.

　　解析：选B　细节理解题。根据第五段第一句"Zeng and his team made the find in 2010 in a remote border region in Tibet"可知，最新的化石是在西藏发现的，故B项正确。

　　30．According to the passage, which of the following statements is TRUE?

A．Some big cats evolved into jaguars 16 million years ago.