This video says about itself:
The echidna is quite unique as it’s a mammal that lays eggs rather than giving birth to live young. This clip is an excerpt from our 1974 production, “Comparative biology of lactation”. A young echidna is called a puggle.
Video transcript available here.
From Smithsonian magazine in the USA:
Watch This Adorable Mammal Hatch From an Egg
A 1974 nature video shows a spiny anteater hatching
By Mary Beth Griggs
Via one of our favorite video blogs, The Kids Should See This, check out this incredible video of an echidna—also known as a spiny anteater—hatching from an egg. Echidnas live in Australia and on the island of New Guinea, and they are some of the only egg laying mammals in existence, along with the fantastically weird platypus.
Australia’s Commonwealth Scientific and Industrial Research Organization, or CSIRO, made this video in 1974. On the organization’s YouTube page, there are many more examples of wonderfully weird old example[s] of animal videos, including vintage favorites like the echidna hatching or a 1965 educational video about the birth of a red kangaroo. (That last one shows the actual birth of a live kangaroo and is not for the faint of heart.)