Mesozoic

• Despite their public image as torpid, lumbering creatures, many dinosaurs were evidently warm-blooded, highly active animals, capable of prolonged and strenuous aerobic exercise.
• In new research, my colleagues and I determined how much energy minibus-sized dinosaurs called Maiasaura used while growing to adulthood.

How bones heal and grow

• Locomotion and weight-bearing activity cause stresses and strains that result in microfractures in the bones.
• Fortunately, the leg bones of dinosaurs – like those of birds, mammals and varanid lizards such as the Komodo dragon – repair themselves in a process known as bone remodelling.
• The main impediment to this research is the shortage of collections of bones from a single dinosaur species at different stages of growth.

‘Good mother reptile’

• Fossils from this formation have yielded much information about the eggs, hatchlings and early lives of a dinosaur named Maiasaura (meaning “good mother reptile”).
• This herbivorous hadrosaur apparently tended her eggs and raised her offspring for more than a year after hatching.

How to measure blood flow from bones

• A decade ago, I wondered whether the size of the foramen could be an indirect measurement of the rate of blood flow to a bone.
• This turned out to be true, and since then the “foramen technique” has been used on fossils to estimate blood flow rate and hence how much energy and nutrients were used in the bones of adult dinosaurs.

Rapid growth doesn’t come cheap

• Blood flow rates calculated from foramen size were similar in one-year-old dinosaurs weighing between 189kg and 455kg and in six- to 11-year-old adults weighing between 1,680kg and 3,200kg.
• In other words, a one-year-old had about four times as much blood flowing to each gram of its shinbone as a full-grown adult did.
• These differences reveal how much more energy and nutrients it took to build bones in the early rapid growth stages of a Maiasaura’s life than it did to maintain the bones in adulthood.

• High-grade copper rich zones are found in the granodiorite porphyry veins as well as skarns within metavolcanics.
• Surface sampling results from surface outcrops and prospect pits in the Copper Ridge area have indicated a potential for high-grade copper, highlighted by grades including 5.03% and 5.43% Cu.
• The Copper Ridge property is located north of the main Pumpkin Hollow property covered by 103 hectares through unpatented and patented claims.
• Follow-up trenching and a reverse circulation drill program are planned to further evaluate these high potential targets.

• Assay results from the infill drilling program at EPO can be found in Table 2 and results from the expansion drilling program in Table 3.
• Drill results from the 27,400 metres drilled at Media Luna in 2022 were released earlier this month (refer to press release dated March 8, 2023 titled Torex Gold Reports Results From Drilling at Media Luna).
• Results from the 2022 infill drilling program at EPO are outlined in Table 2.
• Results from the 2022 expansion drilling program at EPO are outlined in Table 3.

• As at the end of October, assay results for 6,915 m of drilling (60 holes) at El Limón Sur had been received.
• Follow-up drilling below the El Limón Sur open pit has been successful, with multiple intersects of impressive gold, silver and copper assays over favourable core widths (see Figures 2 and 3).
• The Company’s principal asset is the Morelos Complex, which includes the El Limón Guajes (“ELG”) Mine Complex, the Media Luna Project, a processing plant and related infrastructure.
• Commercial production from the Morelos Complex commenced on April 1, 2016 and an updated Technical Report for the Morelos Complex was released in March 2022.