The first complex animals to have ever existed arose during the Ediacaran period (635–540 million years ago). Before then, less complex and single-celled organisms, like sponges and cyanobacteria, ...

The entire Ediacaran tectonic sedimentary framework of the Sichuan Basin was controlled by ... The Kaijiang-Xuanhan paleo-uplift underwent four stages: the incubation period (before the deposition of ...

A Rhoomba vacuum might mimic a hungry lifeform, but researchers have found ancient fossils of one of Earth's first animals, ...

最早出现的复杂动物出现在埃迪卡拉纪（635 亿至 540 亿年前）。在此之前，地球上生活着海绵和蓝藻等不太复杂的单细胞生物。 1970 世纪 564 年代在威尔士卡马森郡进行的一项考古研究中发现的化石最近被确定为 XNUMX 亿年前。这些是最古老的动物化石之一 曾经 ...

Ediacaran; Ꞓ, Cambrian; O, Ordovician ... They underscore the importance of extreme climatic events in the reorganization of terrestrial biodiversity. The 'boring billion' refers to a period in ...

If you’ve ever experienced irregular bowel movements during your period, you’re not alone. Your menstrual cycle can lead to symptoms like bloating, cramping, and changes in your bowel movements.

Though it’s an unexpected symptom, dizziness can occur during your period. Reproductive problems like heavy menstrual bleeding, period pain, and hormonal changes may cause dizziness. Or, the hormonal ...

Cramps aren’t always a sign of menstruation. Many people develop cramps when they don’t have their period. There are various causes of cramps with no period. Issues related to pregnancy are often to ...

Although many methods allow for period-like bleeding, it isn’t necessary. In some cases, bleeding may slow or stop entirely. True menstruation occurs after ovulation when the ovary releases an ...

Late or missed menstrual period Late period: 5 or more days late compared to normal menstrual cycle Missed period: no menstrual flow for more than 6 weeks Teen not using any birth control that stops ...