Was Crocodile stronger at Marineford? Or was he holding back in Alabasta?

 During the Alabasta arc, Crocodile displayed a level of power that was initially considered overwhelming by the Straw Hat Pirates. He possessed the Logia-type Devil Fruit called the Suna Suna no Mi (Sand-Sand Fruit), which granted him the ability to control and transform into sand. He had a reputation as a Shichibukai and controlled the desert kingdom of Alabasta from the shadows. His strength was showcased through his battles with Luffy and others. At Marineford, Crocodile was present as part of the war that took place at Marine Headquarters. While he did participate in the battle, he didn't display the same level of dominance as some other powerful characters present. This has led fans to speculate that he might not have been as strong as initially portrayed in Alabasta. It's important to note that power scaling and character abilities can be subject to interpretation and development by the author. Oda often keeps details deliberately open-ended to keep the story intriguing.

Modern-day dinosaurs still alive

 While dinosaurs as we typically think of them no longer exist, there are species that are considered to be "modern-day dinosaurs" due to their close evolutionary relationship with the ancient reptiles. These species are known as birds, and they are the closest living relatives of the dinosaurs.

Birds evolved from theropod dinosaurs during the Jurassic period, around 150 million years ago. Since then, they have undergone significant changes and have adapted to a wide range of environments, from the Arctic tundra to the tropical rainforest.

Today, there are over 10,000 species of birds, making them one of the most diverse groups of animals on the planet. They are also some of the most well-studied animals, and scientists continue to learn new information about their behavior, biology, and evolution.

So while we don't have actual dinosaurs roaming the earth today, birds are a living testament to the remarkable evolutionary history of these fascinating creatures