Sharks have an evolutionary history extending more than 400 million years, making them one of the oldest vertebrate lineages and predating the emergence of the first true trees by tens of millions of years
Deep time timeline
Fossil evidence and comparative anatomy show that shark ancestors and sharklike fishes were already present in the oceans by the early Devonian and possibly earlier, giving sharks an evolutionary span that stretches back roughly 400 million years or more. Over this vast timeframe, shark lineages diversified into many forms, adapting to different marine niches while retaining core features such as cartilaginous skeletons and specialized sensory systems.
Emergence of trees
Complex land plants evolved later than many marine groups. The first tree forming plants, which developed woody tissues and true trunks capable of supporting significant height, appeared during the late Devonian into the Carboniferous period about 350 to 360 million years ago. The rise of trees transformed terrestrial environments by stabilising soils, creating forest ecosystems and enabling richer terrestrial food webs.
Biological and ecological significance
The fact that sharks predate trees highlights differences in the timing of major evolutionary experiments on Earth. Sharks represent long term success in marine adaptation, surviving mass extinctions and repeatedly radiating into new forms. Trees represent a separate transformational innovation on land that reshaped climate, carbon cycling and habitat structure.
Modern perspective
Today sharks continue to play crucial ecological roles as predators and ecosystem engineers in oceans worldwide, while forests remain central to terrestrial biodiversity and climate regulation. Recognising that sharks existed long before trees emphasises deep time context for conservation and for appreciating how different life forms shaped Earth’s history.
Takeaway
Sharks are among Earth’s most ancient vertebrates, with a lineage that predates the evolution of true trees by tens of millions of years, underscoring both their evolutionary resilience and the staggered timing of major innovations in life’s history.