The discovery team, led by Drs. Ted Daeschler (then of the Philadelphia Academy of Natural Sciences), Neil Shubin (University of Chicago) and the late Farish Jenkins (Harvard), was interested in the evolution of animals with hands and feet, called tetrapods,
from the lobe-finned fish that were common in the Devonian. The first archaic tetrapods lived during the late Devonian Period (Famennian Stage; 372.2–358.9 million years ago) in East Greenland and other Northern European localities. Their closest fish relatives, the elpistostegids including Panderichthys from Latvia and Elpistostege from Quebec’s Gaspé Peninsula, are found earlier in the Devonian, from the latest Givetian
Stage (387.7–382.7 million years ago) to the earliest Frasnian Stage (382.7–372.2 million years ago).
However, these fish lack many of the features present in the earliest tetrapods, so the team set out to find a fossil showcasing a species that better represents a step towards tetrapods. They targeted rocks from an area that preserved the right kind
of fossil environment (aquatic freshwater), the right age (early Frasnian), in the right place (northern hemisphere) but not yet explored by paleontologists. This led them to the Fram Formation of Southeastern Ellesmere Island.
After two unsuccessful field seasons, finding only already well-known fossil fish, they planned one final “do or die” field trip since fieldwork in the high Arctic is logistically challenging and expensive during the limited “summer” season. This last
field trip in 2004 fortunately proved wildly successful.
Name
Tiktaalik comes from a word in Inuktitut that refers to “large, fresh-water fish seen in the shallows.” The name was suggested by the Nunavut Council of Elders (Inuit Qaujimajatuqangit
Katimajiit) and was chosen among the two offered. The specific epithet, roseae, is named in honour of an anonymous benefactor of Devonian paleontology. The fossils are currently held in Ottawa at the Canadian Museum of Nature until research facilities are developed in Nunavut.
Description
The type specimen of Tiktaalik includes a complete skull and the front part of the skeleton; the remaining skeleton is known from additional specimens. Bony scales completely cover the body. The skull is large, triangular from above and covered
by a fine, ridged texture. The eyes are located on the top of the skull, unlike most fish, which have them on the sides of the head. The skull has an outside row of many small, evenly-sized teeth. The inside row and roof of the mouth (palate) have several
large fangs, a pattern common to lobe-finned fish and early tetrapods. The bony connection between the back of the head and the shoulder girdle present in most fish has been lost, creating the first vertebrate neck known from fossil records.
Within their fleshy lobes, the front fins contain the same (homologous) bones as in the arms and wrists of tetrapods, suggesting a shared ancestry. Unique to Tiktaalik, those bones show evidence of having had mobile joints between them.
The hip bone, known as the ilium, is enlarged compared with other closely related fish but lacks a bony connection to the vertebrae. The hip bone called the pubis is similarly expanded and, together with the ilium, forms a socket for the hind fin. However,
the third hip bone, the ischium, remains unossified.
The vertebrae, like in most fish, are made of multiple separate bones that wrap around the notochord, providing reinforcing strength. No fins are found above the vertebrae, unlike most fish. Ribs articulate with each vertebral segment and overlap with
one another to help resist body torsion. There is some evidence for regional differences along the vertebral column, and the ribs near the pelvis were expanded, forming a connection via soft tissues. However, the specialization of the first two vertebrae
for articulating with the back of the skull, common in tetrapods, is absent in Tiktaalik.
Habitat and Diet
The teeth demonstrate a carnivorous diet. The lack of dorsal fins and the eyes on top of the head suggest Tiktaalik might have lurked along the water–air horizon, perhaps near the water’s edge, as an ambush predator.
Recent work using digital models derived from Computed Tomographic (CT) scanning suggests Tiktaalik had a feeding style like the living alligator gar and crocodiles, called lateral (side) snapping. When feeding in water, most fish have mobile
connections between skill bones that help expand the oral cavity to suck food into the mouth. In Tiktaalik and alligator gar, most mobile (kinetic) joints fuse firmly to one another, focusing on a strong bite between the upper and lower jaws.
Mobility is retained in the part of the skull related to the gill chamber, meaning that Tiktaalik exclusively breathed underwater.
Water-to-Land Transition
The very first tetrapods known from the late Devonian were still obligatorily aquatic and remained fish-like in their anatomy. However, older footprint fossils suggest there may still be a missing part of the fossil record left to uncover. In many aspects, Tiktaalik represents an intermediary between these archaic tetrapods and a fully “fish-like” body plan. A neck allows for independent motion of the head. Expanding the hip bones and developing a connection to the vertebrae are essential steps
toward locomotion on land. The development of mobile joints in the fore fin is also necessary for interacting with the ground.
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
