FEMALE PROFESSOR: For years, we thought these were gastroliths-they looked just like gastroliths, and were found in the area of the sauropods' stomachs.

FEMALE PROFESSOR: A recent study measured the gastroliths in modern animals-in ostriches...

FEMALE PROFESSOR: And the study showed that ostriches need to ingest about 1% of their total body weight in gastroliths.

FEMALE PROFESSOR: But we've been able to determine that the stones found with sauropods total much less proportionally... less than a tenth of 1% of their body weight.

FEMALE PROFESSOR: So now, we're not quite sure what these sauropod stones were used for.

请问老师，And the study showed that ostriches need to ingest about 1% of their total body weight in gastroliths. 是不是等于And the study showed that ostriches need to ingest  in gastroliths about 1% of their total body weight？如果是，那么ingest in是不是就等于 ingest，这里的in是不是可有可无？

第二个问题，这里的total 的含义 是不是 （sth）加起来是...的意思，类似的用法还有

  1 a : to produce (a total) when added together

   Donations totaled $120.