Scientists know a lot about this Early Cretaceous ecosystem and the animals and plants that lived here, but there are still things they don't understand well. We asked several Smithsonian scientists what questions they still have, and what new fossil discoveries would help answer them. Scroll down for their answers. You can use the "I would like to know more about..." link to tell us what this painting leaves you wondering about. You can also find out what scientists do when new discoveries contradict the things they thought they already knew.
Kay Behrensmeyer: I would like to know what other Early Cretaceous ecosystems were like. It would help expand our view of the ecology of that time if we had fossils from more sites, especially from drier locations, to see whether they supported different plant and animal communities.
Matt Carrano: So far we just have a small percentage of all the animals that lived here, and for most we have only fragments. I would like to get a much better idea of how many species lived here, as well as what they looked like, and what their closest relatives were. For example, is the Arundel dromaeosaur the same as Deinonychus, from the western US, or more like the species in Europe, Asia, or South America?
Scott Wing: I would like to know more about this early period in flowering plant evolution. What were the early angiosperms like, and how did they get a toe-hold in a landscape dominated by ferns and conifers? As we collect more plant fossils we may discover new species that help us answer these questions.
Nathan Jud: How many plant species lived in this ecosystem? By collecting a lot more plant fossils and paying attention to the rate at which we discover new species, we could estimate how many species remain undiscovered. This is a sampling technique that paleobiologists have learned from ecologists who study species diversity in modern ecosystems.
Who asks??? What about worms and slugs? What soft-bodied organisms lived in this ecosystem? Soft-bodied animals fossilize very rarely , but sometimes their trails or burrows are preserved as trace fossils. Finding and studying more trace fossils from this area would give us clues about soft-bodied creatures that lived here.
What happens when new discoveries contradict old ideas?
Whether they are trying to understand how dinosaurs evolved, what a particular species ate, or how fast it moved, scientists study all the available evidence and offer the best explanation that accounts for all their observations. A "good" explanation stands the test of time and the introduction of new data and new ideas. It allows other scientists to make predictions about what they will find when they examine new fossils or look more closely at old ones. If new observations match predictions, the explanation is supported and strengthened.
Sometimes, though, new evidence contradicts old ideas. Then the old explanations must be modified, or even abandoned. Scientists find this exciting because interpretations that are supported by more complete evidence are more likely to be correct. In the future, if new fossil discoveries reveal errors in this painting, scientists and artists will work together to create a new and more accurate image.
We recently updated some of the dinosaur exhibit mounts at the Smithsonian to reflect new knowledge about the anatomy, stance, and movement of these species. For example, our Camptosaurus (CAMP-toe-SORE-us) displays were originally created before 1920, when the skull of this animal was poorly known and thought to have been long and rectangular. In addition, the arms were positioned far apart across the chest, and the legs were widely spaced. Since then, new discoveries have shown that the skull of Camptosaurus was shorter and had a more triangular snout. The arms are now placed closer together and the hands face palms-in -- this is because most dinosaurs could not rotate their hands far enough to turn their palms down (this outdated pose is commonly depicted). Finally, we placed the feet close together as well, reflecting what we have learned from footprints about their positions during walking.
Find out more
Link to a critique of old National Geographic Dinosaur images by Dr. Thomas R. Holtz, Jr., of the University of Maryland, College Park: http://ngm.nationalgeographic.com/2007/12/bizarre-dinosaurs/holtz-dinosaur-photography
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