What if the Largest Sauropods Survived the KPG Extinction?

Scenario: 66 million years ago, the Earth was struck by a catastrophic event that wiped out the vast majority of dinosaur species - the KPG extinction event. However, a few of the smallest genera of sauropods, including the example of the Magyarosaurus, managed to survive. Refuge in Shadows: These sauropods advantageously leveraged their small sizes to retreat deeper into the forests, caves and crevices - areas too tight or unsuitable for their larger predatory counterparts. There, they found refuge and were able to survive on the sparse foliage and vegetation left devastated by the catastrophic celestial impact. Race Against Time: Fortunately, their smaller size meant their food requirements were less than their larger sauropod cousins. Over time, they evolved to become even smaller and more agile, further enhancing their ability to avoid predators and compete in the new environment dominated by smaller, nimble mammals and birds. Adaptation and Evolution: As millions of years passed, these tiny sauropods evolved more radically in response to their surroundings. Some developed feathers, much like their bird cousins, to aid in temperature control and perhaps even to dazzle potential mates, a similar progression to certain theropods. These feathered sauropods remained herbivorous, filling the niche of small, browsers of low-level vegetation. Living in Harmony: Other species of small sauropods discovered advantages in cooperation with the evolving mammalian species, adopting communal, pack-related behaviors for hunting and protection. The rapid evolutionary pressures also led to increased cerebral development, making these remaining sauropods smarter and more adaptable to changing climates and threats. The modern-day tableau of our planet would thus be radically different. Alongside the diverse world of birds, mammals, and reptiles, a unique branch of miniaturized, highly adapted sauropods still roam the Earth, a testament to the hardy survivability of life. Their continued existence would provide an invaluable window into the world of dinosaurs, a world thought to be completely lost at the end of the Cretaceous period. Their survival would not only challenge our understanding of evolution but also diversify the terrestrial biomes on the Earth. Dinosaurs would no longer be exclusively exhibits in a museum, but living breathing creatures, offering a staggering array of new opportunities for fields like biochemistry, paleontology and natural history.