**living proof** 

> *living proof* [*phrase*]: [usually 'verb-link _phrase_', often '_phrase_ that'_, '_phrase_ of noun']
> 
> If you say that someone is living proof of something, you mean that
> their actions or personal qualities show that a particular fact is
> true or that a particular quality exists.
> - *He is living proof that some players just get better with age.*

[[Collins Cobuild Advanced Learner's Dictionary](https://www.collinsdictionary.com/dictionary/english/living-proof)]

> *living proof*
> 
> If someone is living proof of a particular fact, they are a good
> example of how true it is....
> - *I will remember them as living proof that you can have too much of a good thing.*



[[Longman Dictionary of Contemporary English](https://www.ldoceonline.com/dictionary/living-proof)]

Though usually applied to persons (He / she / you ... is / are living proof ...), the usage is broadened to human institutions:

> - *The stock exchange is living proof of that fact.*

[[Cambridge Dictionary; Hansard](https://dictionary.cambridge.org/example/english/living-proof)]

> - *It is living proof that public services can be both efficient and popular.*

[[Hansard: National Health Service {50th Anniversary}](https://hansard.parliament.uk/commons/1998-07-01/debates/3e7697bd-4007-42e3-a199-2e19ff2c8a27/NationalHealthService(50ThAnniversary))] 

Admittedly, there were zero hits in a Google search for "It is living proof" + "existence of dinosaurs"!