# Pacific origin of pantropical shrimp > Live situation record from CLSTR: https://clstr.news/situations/pacific-origin-of-pantropical-shrimp > Updated: 2026-08-03T12:39:53.000Z. Sources: 4. Developments: 2. In late July 2026, researchers from Spain's Consejo Superior de Investigaciones Científicas (CSIC) published a study in the Journal of Biogeography that dated the most recent common ancestor of modern pantropical shrimp to the Eastern Pacific about 125 million years ago. Using a fossil‑calibrated phylogeny, molecular markers and continuous‑space statistical models on over 34,000 records of 155 species, the team showed that long‑distance dispersal, rather than static geographic barriers, drove the shrimp’s spread across the Atlantic, Oceania and Southeast Asia. The findings overturned the long‑standing hypothesis that shrimp evolved in the ancient Tethys Sea and highlighted accelerated dispersal near the Cretaceous‑Paleogene boundary. A few days later, the same CSIC team released a follow‑up description emphasizing the new modelling approach’s unprecedented spatial resolution. Lead co‑author Mónica Núñez‑Flores noted that the model not only clarifies historic biogeographic patterns but also offers a tool for predicting how contemporary marine ecosystems may respond to environmental change. The second release reinforced the original conclusions while extending their relevance to future ecological forecasting. ## Timeline ### 2026-08-03: CSIC Study Traces Shrimp Evolution to Pacific Origin CSIC researchers show shrimp originated in the Eastern Pacific 125 M years ago and spread globally via long‑distance dispersal, challenging the old Tethys‑origin theory. 2 sources. https://clstr.news/cluster/csic-study-traces-shrimp-evolution-to-pacific-origin ### 2026-07-31: CSIC Study Traces Shrimp Origins to Pacific 125 Million Years Ago A Spanish‑led study finds shrimp ancestors originated in the Eastern Pacific 125 million years ago, spreading worldwide via long‑distance routes and challenging the classic Tethys‑origin theory. 2 sources. https://clstr.news/cluster/csic-study-traces-shrimp-origins-to-pacific-125-million-years-ago --- Cite as: Pacific origin of pantropical shrimp. CLSTR, https://clstr.news/situations/pacific-origin-of-pantropical-shrimp