Even as some scientists search for signs of life beyond Earth, other researchers have been discovering new species on our own humble planet faster than ever before.
From high up in the mountains to the deep sea, take a tour across the world to meet five new species discovered in 2025.
An ancient sea cow in the Persian Gulf
Cows often get a bad rap for contributing to greenhouse gas emissions, but a newly discovered species of their ocean counterparts suggests that sea cows have been key contributors to a natural climate change solution for the past 21 million years.
This long-extinct sea cow's fossil remains were discovered in Al Maszhabiya, Qatar, which is now known to be the richest fossil sea cow deposit in the world. Like today's manatees and dugongs, it mainly grazed on seagrass and was considered an "ecosystem engineer" in the coastal waters of the Persian Gulf, where it primarily lived.
With their fleshy muzzles, these mammals would browse the seafloor, grab the plants, and use their tusks to snip the roots and eat them. In the process, they lift up nutrients from the seafloor that would otherwise be buried, which other animals in the ecosystem can use. These nutrients, in addition to the sea cow's excrement, help cultivate a healthier and more diverse ecosystem.
"Supporting seagrass communities through ecosystem engineering is a great natural climate solution, because seagrass communities store an incredible amount of carbon," says Nicholas Pyenson, curator of fossil marine mammals at the Smithsonian's National Museum of Natural History.
The name of the new species, Salwasiren qatarensis, honors the fossil's discovery site in Qatar, and the Bay of Salwa in the Persian Gulf, where the largest herd of dugongs can be found today. But Pyenson says Salwa, an Arabic word which roughly translates to "solace," is also a nod to the potential for the new species to "elevate the visibility and protection of natural heritage," adding that "natural heritage doesn't actually, in all cases, respect geopolitical boundaries."
Pyenson is referring to the fact that the seagrass meadow in the Bay of Salwa spans the coasts of Qatar, Saudi Arabia and Bahrain. His colleagues are currently in the process of applying for UNESCO World Heritage status to protect the region.
"This is a great example of science diplomacy," Pyenson says, "where data sharing, making data open access and available when you publish, has the potential to actually form a metaphorical bridge between countries that maybe have not historically seen eye to eye."
You can see a 3D model of the sea cow fossil here.
A mini marsupial in the Andes Mountains
A beady-eyed mouse opossum living high up in the Peruvian Andes wasn't what Silvia Pavan initially set out to find during her expedition in Río Abiseo National Park, but the new species gives yet another reason why this special region is protected as a UNESCO World Heritage site.
Pavan, an assistant professor at Cal Poly Humboldt, was on the hunt for a specific squirrel species when she and her colleagues came across an animal they eventually named Marmosa chachapoya to honor the Chachapoya people who formerly occupied the area.
The tiny marsupial (which, despite its scientific name, is not a marmoset) was the first small mammal that the researchers collected on their trip. While the animal looked a lot like a mouse opossum, its long and delicate snout and home high in the mountains set it apart from other marmosa species. But once Pavan brought the samples back, DNA analysis — coupled with a close examination of its skull — proved that this was indeed a new species.
The high-altitude area of the mountains where the expedition took place is difficult to access, but Pavan says these underexplored areas are even more important to study: "We do not know yet completely what we have, and it highlights how much we still need to explore and study the area, and how unique and important [it] is for biodiversity."
With the threat of climate change and human impact, Pavan says, "the species are being lost before we know they exist."
On this trip alone, the team of researchers collected roughly 100 different specimens that they are continuing to identify.
An undercover spider in Northern California
Marshal Hedin was walking along the river near where he grew up in Northern California when he came across a spider he hadn't seen before. Fifteen years later, the professor of biology at San Diego State University finally got to identify it as a new species of an entirely new genus, which he named after his home of Siskiyou County.
Brown spider species like Siskiyu armilla are very difficult to tell apart using only their physical characteristics. Many species look similar because they live in the same kind of habitat: under rocks or in other dark, humid places.
To make sure the spider Hedin found was genetically different from existing species, he and his colleagues decided to perform a DNA analysis. So he returned to the river to search for a new specimen of the rare spider (and brought his son along with him too).
Coauthor Rodrigo Monjaraz Ruedas, an assistant curator of entomology at the Natural History Museum in Los Angeles who focused on the DNA analysis, was surprised to find that there was such a huge diversity of spider species in the area.
He says that if we simply assume that spiders that look similar are the same species without actually examining their DNA, "we're going to be missing a lot of the actual diversity these spiders have."
California plays an especially important role in this diversity, according to Monjaraz Ruedas. As part of a project from the California Institute of Biodiversity, which hasn't yet been published, he has found that close to 40% of the total number of described species of spiders in the U.S. can be found in the state.
Hedin, who was once oblivious to the diversity of species his home boasts, says that this journey has brought him full circle: "Now I know that it's a very unique place." He hopes that this discovery shows the other folks living along the river how special their home is.
And "this is just the tip of the iceberg," Monjaraz Ruedas says, because they're still examining 40 to 50 other spiders that might also be new species.
A smiley snailfish from the deep sea
Nearly 11,000 feet into the deep sea, scientists discovered a new species that caught the attention — and affection — of viewers from around the world. The bumpy snailfish was captured on video by researchers at the Monterey Bay Aquarium Research Institute during their expedition off the shores of Central California — and with its big eyes, feathery fins and a mouth bearing the suggestion of a smile, it was an instant hit.
To help determine if the floppy pink sea creature was new or one of the 400 existing species of snailfish, they assembled a team of scientists, including Mackenzie Gerringer, an associate professor of biology at the State University of New York at Geneseo.
Even though Gerringer has "never met a snailfish [she] didn't love," she knows that the deep sea, where some of the species live, is seen as a bit of an alien environment by many people, which can come with a negative connotation.
She says the new species can help people question their assumptions about the deep sea because "you're left with these fishes that are, in my opinion, quite cute, and they really look quite fragile in an environment that we think of as being very harsh."
The research team also identified two other species of snailfish, which Gerringer says highlights just how much there still is to learn about the deep sea.
While discovering a new species can be very exciting, Gerringer believes the importance of the practice goes beyond that.
"It's critical to know who is in these ecosystems, so that we can understand how they're working, so that we can protect habitats like the deep sea that we know play hugely important roles," she says. Some of those roles, including the deep sea's ability to store enormous amounts of carbon, are especially important given the threat of climate change.
Live-birthing toads in Tanzania
Many people remember learning about the typical life cycle of frogs and toads in elementary school: Eggs turn into tadpoles, which eventually become adults. But scientists have found three new species of toads in Tanzania that do something very unusual: they give birth to live young.
Another striking thing about these new species, which are all part of the genus Nectophrynoides: The journey to discover them took over 100 years. The first toad in this genus was described in the early 1900s, and because all the specimens collected looked so similar, they were all thought to belong to a singular species.
But Christoph Liedtke, an academic researcher from the Spanish National Research Council who has spent the last decade studying these toads, wondered whether there was more biodiversity in the highlands of the Eastern Arc mountains of Tanzania than previously thought. So he and his colleagues tried to see if there was more than one species in the Nectophrynoides genus.
This was no easy task because many of the specimens they needed to examine and compare to modern-day samples were collected before the time of DNA sequencing. Coauthor John Lyakurwa, an assistant lecturer at the University of Dar es Salaam, says that the process was like a "big puzzle that we had to solve."
So they teamed up with researchers from Denmark and Belgium to extract DNA from over 200 museum specimens. From there, they used next-generation sequencing to identify three new species in the genus, which was more than previously thought.
It's not clear how these toads will fare in the future. Like many species, their populations are in decline, with one species already extinct and others not being spotted for the past 20 years. For his PhD thesis, Lyakurwa has been focusing on understanding why these toad populations have been shrinking. Especially because of their unusual method of reproduction, he stresses that "if we lose them, we lose a very big evolutionary history."
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