Complex sentence: In 1993, "M. sinocanadorum" was described based on a skull and the first four cervical vertebrae; this species possessed the longest cervical rib of any described sauropod dinosaur, measuring 4.1 m (13.5 ft).
Split into simpler sentences: In 1993, "M. sinocanadorum" was described, which consisted of skull material and the first four cervical vertebrae. This species possessed the longest cervical rib of any described sauropod dinosaur, measuring 4.1 m (13.5 ft).