TT #171 · Parshas Shemini · Aliyah 5 · Passuk 31
Chabad.org — Vayikra Chapter 11 with Rashi
English: These are the impure among the swarming things; whoever touches them when dead shall be impure until evening.
Chullin 128b.
E-Daf.com — Chullin 128b (Tsurras Hadaf)
Textual definition — The word “sheretz” defines the bodily components required for the corresponding impurity.
Detached flesh of a sheretz is treated as sheretz material for this law when it includes flesh, sinews, and bones as defined by the derashah.