Different Types of Twins

[ysabetwordsmith]

There's more to twinning than merely identical or fraternal twins.  Watch a video or read an article about more types. 

Comments

[(Anonymous)]

At one point I was trying to figure out if you could tell the twin type in egg-laying species could be determined by whether or not they came from a shared egg. And how viable a shared-egg twin set would be - I'm guessing not very. Human preemies tend to be early, and preemie baby birds...can have some very serious issues.

About the only useful result of this research:
- I know more-than-average about midwifing chicken eggs (in theory)
- I know why reptile and bird eggs require different types of incubators
- I learned that babies can learn (and communicate!) from inside the egg
- I found this adorable video of hatching baby crocs:
https://m.youtube.com/watch?v=GxHWp1A_ABg

I never did quite figure out the answer to my original question.

Thoughts

[ysabetwordsmith]

>> At one point I was trying to figure out if you could tell the twin type in egg-laying species could be determined by whether or not they came from a shared egg. <<

If they share an eggshell, they're monoamniotic twins, thus likely identical. But it is probably also possible for identical twins that split early enough to form separate shells, like biamniotic twins in humans. All the eggs from one clutch, or all the babies in a litter, are fraternal multiples.

>>And how viable a shared-egg twin set would be - I'm guessing not very. Human preemies tend to be early, and preemie baby birds...can have some very serious issues.<<

It's a long shot, because there is both less food and less space inside a rigid shell. But it's been observed in chickens and some other birds.

Re: Thoughts

[(Anonymous)]

>>If they share an eggshell, they're monoamniotic twins, thus likely identical. But it is probably also possible for identical twins that split early enough to form separate shells, like biamniotic twins in humans.<<

That's roughly what I figured.

>>All the eggs from one clutch, or all the babies in a litter, are fraternal multiples.<<

Cats can have the half-sibling littermate thing quite easily. (I occasionlly wondered, with the last pair of sibling kitties I had...they were that different.)

>>It's a long shot, because there is both less food and less space inside a rigid shell. But it's been observed in chickens and some other birds.<<

I know I've occasionally heard of conjoined birds, but I'd mostly be worried about the final stages of organ development.

With humans, the last few stages affect muscle tone, size and ability to breathe.

With baby chickens, at least, the last few stages involve absorbing a yolk, and finishing the abdominal wall.

In either case don't yank anything, because if the placenta/eggshell disconnects before it is time, you can get serious uncontrolled bleeding. And possibly give someone an infection...

[pronker]

Fascinating article. A facetious term I learned recently is "Irish twin," which means two births to one mother within one year. If one or both of the births are twins, would the term be "double Irish twins"? This is similar to "double first cousins," which occurs when two brothers marry two sisters. *ponders*