Here are two ways to proceed out of many possibilities out there:
The moment you changed companies (or the parties that were responsible for your payment changed), your experience with the first ended and that with your second began.
This automatically gives you experience with two companies, and that's good.
Also, if your previous employer was large, you can state that on your resume, thereby adding more value than the lesser-known company that made the acquisition.
If this happened in a short term, you may be perceived as a job hopper.
In your description of second company, mention that it acquired your team from the previous one, and then, if possible, list out your achievements/projects post the acquisition.
State complete experience as being under the new company. Considering that your team hasn't changed, your experience would have been one continuous stretch from when you began working in the team.
PROS: Continuous experience can be perceived as loyalty. Also, you get to talk about your whole duration of your stay with the team in one shot during your interview, highlighting some of your greatest accomplishments on the team.
CONS: You may be perceived as hiding something, and may goof up if asked about people at company Z before the acquisition.
Highlight that you were on team X, formerly with company Y, until the acquisition of your awesome team by company Z. You're still in team X, but with Z.
For instance, people who worked in YouTube may now claim to be working with Google, or Alphabet Inc. even though nothing much may have changed about the work they do.
Disclaimer: I am not a lawyer, and this is not legal advice. Your resume is merely a ticket to an interview, which is the real place that you've to impress people. The decision rests with you. So, good luck!