The dinosaurs were brought back about 35 years ago, through technology researched by Dr. Philip Richards, a microbiologist, and researcher at Berkley. It was Dr. Richards who took a sample of dinosaur DNA from a well-preserved fossil and mapped the genome that enabled him to resurrect the species. Once the first was achieved, the DNA was altered to grow new ones, using monitor lizards and crocodiles as the hosts. Botanists were able to use similar techniques to resurrect long-extinct plants.
Nothing unusual comes up about New York or Central Park. No disappearances of note or mass events.
Interestingly, however, Dr. Richard's work is currently being improved upon to alter children at the genetic level while still in the womb. The science is still rudimentary, but a successful chimera (a girl with cat ears and a tail) has already been born in China. The fear is that this could lead to a race of "superbeings" genetically engineered to be stronger, faster, and more resilient than ordinary humans. Most countries in the UN have outlawed genetic manipulation, but some are actively researching it. In the words of Dr. Richards himself, "The genie is out of the bottle, and I wish to God that I could imprison it again."