What major difficulty arises when paleontologists try to trace the ancestor using skeletal features?
Answer
Primitive structures like jaw suspension and the internal skeleton are made of cartilage, which rarely fossilizes well.
The most primitive structures, such as the arrangement of the jaw suspension or the structure of the internal skeleton, are often made of cartilage, which rarely fossilizes well compared to bone.

#Videos
Why This Shark Hasn't Changed in 80 Million Years - YouTube
Related Questions
What specialized term is used to label the frilled shark due to its unchanging morphology over vast geological history?How many recognized living species belong to the genus *Chlamydoselachus*?Approximately how long ago do fossil evidence for the *Chlamydoselachus* genus date back, placing its form in a specific geological period?Approximately how many slender, three-pronged teeth does the frilled shark possess, arranged in multiple rows?How many gill slits does the frilled shark possess, and where is the first one uniquely positioned?What was the primary difference noted between the extinct *Chlamydoselachus goliath* and the modern *C. anguineus*?What ecological factor explains why the frilled shark lineage has maintained a stable morphology over deep time?How are the frilled shark's needle-like teeth specialized for feeding in its habitat?What major difficulty arises when paleontologists try to trace the ancestor using skeletal features?Which statement accurately describes the evolutionary branching pattern suggested by comparing *C. goliath* and *C. anguineus*?Which species is identified as the closest living relative to *Chlamydoselachus anguineus*?