First, there are the yearly growth rings in the trees.

首先，树上有年轮。

Many scientists also consider tree growth rings and ice samples.

许多科学家还考虑树木的生长轮和冰样本。

They determined that bands form in the shark vertebrae every year, like a tree's growth rings.

他们确定，每年鲨鱼的椎骨都会形成条纹，就像树木的年轮一样。

You see, the annual growth rings here show the presence of the stable isotope Nitrogen-15, which significantly comes from the oceans.

你看，这里每年增加的年轮显示出氮的稳定同位素：氮-15的存在这意味着这些氮来自于海洋。

They looked kind of like growth rings, like what you find in modern trees.

它们看起来有点像年轮，就像你在现代树木中发现的那样。

Using a laser to carefully count the number of growth rings in a 70-million-year-old fossil might seem like quite a laborious way to find out the number of days in a year.

为了确定一天有多少天，用激光细数7000万年前化石的年轮，似乎是相当费劲的方法。

For instance, when a new pulse of magma comes into the chamber -- potentially triggering an eruption -- it often has a slightly different chemistry, which is recorded in the growth ring.

例如，当一股新的岩浆脉冲进入岩浆室时——可能会引发喷发——它的化学成分通常会略有不同，这会记录在年轮中。

Growth rings are thickening of the bone that indicates periods of time when the dinosaurs weren't rapidly growing. These growth rings are evidence that dinosaurs stopped growing or grew more slowly during cooler periods.

年轮是骨骼的增厚，表明恐龙没有快速生长的时期。这些年轮是恐龙在寒冷时期停止生长或生长更慢的证据。