Early Land Animals Lacked Good Bites

Early Land Animals Lacked Good Bites
早期陆生动物缺乏好牙口
What had the legs of a ‘gator and the jaws of a fish? Why, the earliest land animals. Because a new study shows that animals evolved weight-bearing limbs long before they had the chompers to really take advantage of a terrestrial diet. The research is in the journal Integrative and Comparative Biology. [Philip S. L. Anderson, Matt Friedman and Marcello Ruta, Late to the Table: Diversification of Tetrapod Mandibular Biomechanics Lagged Behind the Evolution of Terrestriality]
什么动物有鳄鱼的腿和鱼的颚？早期的陆生动物。因为一项新的研究表明，动物早在拥有吃陆地食物很久之前，就已经有可以负重的四肢了。研究发表在 journal Integrative and Comparative Biology. [Philip S. L. Anderson, Matt Friedman and Marcello Ruta, Late to the Table: Diversification of Tetrapod Mandibular Biomechanics Lagged Behind the Evolution of Terrestriality]
Scientists had suspected that the first four-legged creatures to haul their carcasses out of the ocean didn’t belly up to the salad bar straight away. But they lacked definitive proof.
科学家们怀疑首个从海洋进化而来的四足生物不能直接嚼沙拉条。但是他们缺乏权威的证据。
Now, researchers have carefully examined the fossilized faces of 89 beasties that lived on land and sea some 300 [million] to 400 million years ago. They probed the jaws for a range of biomechanical features, such as how much force they could give to their bite. The result: seems it took tens of millions of years after setting foot on land to come up with a mouth that could munch on the greenery. 
现在，研究人员仔细检查了3～4亿年前生活在陆地和海洋的89种动物的化石。他们检测了这些动物的颚的生物化学特性，比如他们嚼食物时能使用多大劲儿。结果是：他们花了几千万年才进化出嘴巴，能力吃绿色植物。
Why the lag? Could be the critters had to stop being such mouth breathers and shift from using gills to using lungs, which freed their jaws to develop in new ways. And which left no more excuses to not eat their veggies.
为什么牙口不好呢？可能是他们必须停止用嘴呼吸，并用肺来取代腮的原因，这样就把他们的颚解放出来，以新的方式发展。这样就没有理由不吃蔬菜了。